Instr for Form CT-1x--2021-03-00

Instructions for Form CT-1 X

Department of the Treasury
Internal Revenue Service

(Rev. March 2021)

Adjusted Employer's Annual Railroad Retirement Tax Return or Claim for Refund
Section references are to the Internal Revenue Code
unless otherwise noted.

Future Developments

For the latest information about developments related to
Form CT-1 X and its instructions, such as legislation
enacted after they were published, go to IRS.gov/CT1X.
The March 2021 revision of Form CT-1 X updates
TIP Form CT-1 X to allow it to be used to make
corrections to the coronavirus (COVID-19) related
employment tax credits and other relief. You may use this
revision of Form CT-1 X and its instructions to correct
Form CT-1 for all years for which the statute of limitations
on corrections hasn't expired.

What's New
Changes to Form CT-1 X for COVID-19 related employment tax credits and other tax relief. Form CT-1
X has been significantly revised to allow for correcting
COVID-19 related employment tax credits and other tax
relief related to COVID-19 reported on Form CT-1. You
may now use Form CT-1 X to report corrections to the
following items reported on Form CT-1.
• Corrections to amounts reported on Form CT-1, lines
16, 23, 30, 31, 32, and 33, for the credit for qualified sick
and family leave compensation are now reported on Form
CT-1 X, lines 19, 24, 27, 28, 29, and 30, respectively. For
more information about the credit for qualified sick and
family leave compensation, including the dates for which
the credit may be claimed, go to IRS.gov/PLC.
• Corrections to amounts reported on Form CT-1, lines
17, 24, 34, and 35, for the employee retention credit are
now reported on Form CT-1 X, lines 20, 25, 31, and 32,
respectively. For more information about the employee
retention credit for qualified wages paid after March 12,
2020, and before January 1, 2021, see Notice 2021-20,
2021-11 I.R.B. 922, available at IRS.gov/irb/
2021-11_IRB#NOT-2021-20.
• Corrections to the deferred amount of the Tier 1
Employer tax reported on Form CT-1, line 21, are now
reported on Form CT-1 X, line 22. For more information
about the deferral of employment tax deposits, including
the dates that deposits were allowed to be deferred and
when they must be paid, go to IRS.gov/ETD.
• Corrections to the deferred amount of the Tier 1
Employee tax reported on Form CT-1, line 22, are
reported on Form CT-1 X, line 23. For more information
about the deferral of Tier 1 Employee tax, including the
dates that the taxes were allowed to be deferred and
when they must be paid, see Notice 2020-65, 2020-38
I.R.B. 567, available at IRS.gov/irb/
2020-38_IRB#NOT-2020-65, and Notice 2021-11,
2021-06 I.R.B. 827, available at IRS.gov/irb/
2021-06_IRB#NOT-2021-11.

Mar 15, 2021

Note. If a line on Form CT-1 X doesn’t apply to you, leave
it blank. If you’re correcting a year that began before 2020,
you must leave blank the new lines 19, 20, 22, 23, 24, 25,
27, 28, 29, 30, 31, and 32.
If you claimed the credit for qualified sick and

TIP family leave compensation and/or the employee

retention credit on your original 2020 Form CT-1,
and you make any corrections on Form CT-1 X for 2020 to
amounts used to figure these credits, you will need to
refigure the amount of these credits using Worksheet 1,
later. You will also use this worksheet to figure these
credits if you’re claiming them for the first time on Form
CT-1 X.

Reminders
Employee consents to support a claim for refund.
Rev. Proc. 2017-28, 2017-14 I.R.B. 1061, available at
IRS.gov/irb/2017-14_IRB#RP-2017-28, provides
guidance to employers on the requirements for employee
consents used by an employer to support a claim for
refund of overcollected Railroad Retirement Tax Act
(RRTA) taxes. The revenue procedure clarifies the basic
requirements for both a request for employee consent and
for the employee consent, and permits a consent to be
requested, furnished, and retained in an electronic format
as an alternative to paper format. The revenue procedure
also contains guidance concerning when an employer
may claim a refund of only the employer share of
overcollected RRTA taxes. The revenue procedure
requires that any request for consent include an Additional
Medicare Tax notice indicating that any claim on the
employee’s behalf won’t include a claim for overpaid Tier
1 Employee Additional Medicare Tax.
Correcting Tier 1 Employee Additional Medicare Tax
withholding and compensation subject to Tier 1 Employee Additional Medicare Tax withholding.
Compensation (including tips) and sick pay subject to Tier
1 Employee Additional Medicare Tax withholding are
reported on Form CT-1, lines 6 and 12. Certain errors
discovered on a previously filed Form CT-1 are corrected
on Form CT-1 X, lines 11 and 17. However, you can’t file
Form CT-1 X to correct Tier 1 Employee Additional
Medicare Tax actually withheld from an employee in a
prior year. See the instructions for lines 11 and 17, later,
for more information on the types of errors that can be
corrected and how the correction is reported on Form
CT-1 X. For more information about Tier 1 Employee
Additional Medicare Tax withholding, see the Instructions
for Form CT-1 or go to IRS.gov/ADMT.

Cat. No. 20339E

Report the correction of underreported and
overreported tax amounts for the same tax period on a
single Form CT-1 X, unless you’re requesting a refund or
abatement. If you’re requesting a refund or abatement and
are correcting both underreported and overreported tax
amounts, file one Form CT-1 X correcting the
underreported tax amounts only and a second Form CT-1
X correcting the overreported tax amounts.

General Instructions:
Understanding Form CT-1 X
What Is the Purpose of Form CT-1 X?
Use Form CT-1 X to correct errors on a previously filed
Form CT-1. Use Form CT-1 X to correct:
• Tier 1 Employee tax, Tier 1 Employee Medicare tax,
Tier 1 Employee Additional Medicare Tax, and Tier 2
Employee tax;
• Tier 1 Employer tax, Tier 1 Employer Medicare tax, and
Tier 2 Employer tax;
• Deferred amount of the Tier 1 Employer tax;
• Deferred amount of the Tier 1 Employee tax;
• Amounts reported on Form CT-1 for the credit for
qualified sick and family leave compensation, including
adjustments to Form CT-1, lines 16, 23, 30, 31, 32, and
33; and
• Amounts reported on Form CT-1 for the employee
retention credit, including adjustments to Form CT-1, lines
17, 24, 34, and 35.

You’ll use the adjustment process if you underreported
RRTA taxes and are making a payment, or if you
overreported RRTA taxes and will be applying the credit
to Form CT-1 for the period during which you file Form
CT-1 X. However, see the Caution under Is There a
Deadline for Filing Form CT-1 X?, later, if you’re correcting
overreported tax amounts during the last 90 days of a
period of limitations. You’ll use the claim process if you
overreported RRTA taxes and are requesting a refund or
abatement of the overreported tax amount. Follow the
chart on page 5 of Form CT-1 X for help in choosing
whether to use the adjustment process or the claim
process. Be sure to provide a detailed explanation on
line 35 for each correction that you show on Form CT-1 X.

Use Form 843, Claim for Refund and Request for
Abatement, to request a refund or abatement of assessed
interest or penalties. Don’t request a refund or abatement
of assessed interest or penalties on Form CT-1 or Form
CT-1 X.

Continue to report current year adjustments on Form
CT-1, line 14.
You have additional requirements to complete when
filing Form CT-1 X, such as certifying that you filed (or will
file) all applicable Forms W-2, Wage and Tax Statements,
and Forms W-2c, Corrected Wage and Tax Statements,
with the Social Security Administration (SSA). For
corrections of overreported Tier 1 and Tier 2 taxes, you
must make any certifications that apply to your situation.

We use the terms “correct” and “corrections” on

TIP Form CT-1 X and in these instructions to include

interest-free adjustments under sections 6205 and
6413 and claims for refund and abatement under sections
6402, 6414, and 6404. See Rev. Rul. 2009-39 for
examples of how the interest-free adjustment and claim
for refund rules apply in 10 different situations. You can
find Rev. Rul. 2009-39, 2009-52 I.R.B. 951 at IRS.gov/irb/
2009-52_IRB#RR-2009-39.

Be sure to give us a detailed explanation on line 35 for
each correction you show on Form CT-1 X.
Don’t use Form CT-1 X to correct Form 941,
941-SS, 943, 944, or 945. Instead, use the "X"
CAUTION form that corresponds to those forms (Form
941-X, 943-X, 944-X, or 945-X).

!

When you discover an error on a previously filed Form
CT-1, you must:
• Correct that error using Form CT-1 X;
• File a separate Form CT-1 X for each Form CT-1 that
you’re correcting; and
• Generally, file Form CT-1 X separately. Don’t file Form
CT-1 X with Form CT-1. However, see the instructions for
line 34, later, for an exception.

Where Can You Get Help?
For help filing Form CT-1 X or for questions about RRTA
taxes and tax corrections, you can:
• Go to IRS.gov/EmploymentTaxes, and IRS.gov/
CorrectingEmploymentTaxes;
• See Pub. 15, Employer's Tax Guide; or
• Call the IRS Business and Specialty Tax Line toll free at
800-829-4933 or 800-829-4059 (TDD/TTY for persons
who are deaf, hard of hearing, or have a speech
disability), Monday–Friday from 7:00 a.m. to 7:00 p.m.
local time (Alaska and Hawaii follow Pacific time).

If you didn’t file a Form CT-1 for 1 or more years, don’t
use Form CT-1 X. Instead, file Form CT-1 for each of
those years. See also When Should You File Form CT-1
X, later. However, if you didn’t file Forms CT-1 because
you improperly treated workers as independent
contractors or nonemployees and are now reclassifying
them as employees, see the instructions for line 34, later.

See also How Can You Get Forms, Instructions, and
Publications From the IRS?, later.

Unless otherwise specified in these instructions,

When Should You File Form CT-1 X?

TIP an underreported employment tax credit or Tier 1

tax deferral should be treated like an overreported
tax amount. An overreported employment tax credit or
Tier 1 tax deferral should be treated like an underreported
tax amount. For more information, including which
process to select on lines 1 and 2, see Correcting an
employment tax credit or Tier 1 tax deferral, later.

File Form CT-1 X when you discover an error on a
previously filed Form CT-1.
However, if your only errors on Form CT-1 relate to
RRTA tax liabilities reported in Part II of Form CT-1 or on
Form 945-A, Annual Record of Federal Tax Liability, don’t
file Form CT-1 X. To correct federal tax liabilities reported
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Instructions for Form CT-1 X (Rev. 3-2021)

in Part II of Form CT-1, file Form 945-A, but only enter the
monthly totals. The daily entries aren’t required. For more
information about correcting RRTA tax liabilities reported
on Form 945-A, see the Form 945-A instructions.

Overreported tax—Adjustment process. If you
overreported tax and choose to apply the credit to Form
CT-1, file an adjusted return on Form CT-1 X as soon as
possible after you discover the error but more than 90
days before the period of limitations on the credit or refund
for Form CT-1 expires. See Is There a Deadline for Filing
Form CT-1 X, later.

Due dates. The due date for filing Form CT-1 X depends
on when you discover an error and if you underreported or
overreported tax. If you underreported tax, see
Underreported tax, later. For overreported tax amounts,
you may choose to either make an interest-free
adjustment or file a claim for refund or abatement. If you’re
correcting overreported tax amounts, see Overreported
tax—adjustment process or Overreported tax—claim
process, later.
If any due date falls on a Saturday, Sunday, or legal
holiday, you may file Form CT-1 X on the next business
day. The term “legal holiday” means any legal holiday in
the District of Columbia. See Pub. 15 for the list of legal
holidays. If we receive Form CT-1 X after the due date, we
will treat Form CT-1 X as filed on time if the envelope
containing Form CT-1 X is properly addressed, contains
sufficient postage, and is postmarked by the U.S. Postal
Service on or before the due date, or sent by an
IRS-designated private delivery service (PDS) on or
before the due date. If you don’t follow these guidelines,
we will consider Form CT-1 X filed when it is actually
received. For more information about PDSs, see Where
Should You File Form CT-1 X, later.

Form CT-1 X can’t be used to correct
overreported amounts of Tier 1 Employee
CAUTION Additional Medicare Tax unless the amounts
weren’t withheld from employee compensation.

!

Example—You want your credit applied to Form
CT-1. You filed your 2020 Form CT-1 on February 23,
2021, and payments were timely made. On May 4, 2021,
you discover that you overreported tax on your 2020 Form
CT-1. You file Form CT-1 X on June 1, 2021, and check
the box on line 1 to indicate you want to use the
adjustment process. The IRS treats your credit as a tax
deposit made on January 1, 2021. When you file your
2021 Form CT-1, include the amount from Form CT-1 X,
line 26, on the “Total railroad retirement tax deposits” line
of your 2021 Form CT-1.
Overreported tax—Claim process. If you overreported
tax on Form CT-1, you may choose to file a claim for
refund or abatement on Form CT-1 X any time before the
period of limitations on credit or refund expires on Form
CT-1. If you also need to correct any underreported tax
amounts, you must file another Form CT-1 X reporting
only corrections to the underreported tax amounts. See Is
There a Deadline for Filing Form CT-1 X, later.

Underreported tax. If you’re correcting underreported
tax, you must file Form CT-1 X by the due date of the
return for the return period in which you discovered the
error and pay the amount you owe by the time you file.
Filing and paying on time generally will ensure that your
correction is interest free and not subject to failure-to-pay
(FTP) or failure-to-deposit (FTD) penalties. See What
About Penalties and Interest, later. For details on how to
make a payment, see the instructions for line 26, later.
If Form CT-1 X is filed late (after the due date of the
return for the return period in which you discovered the
error), you must attach an amended Form 945-A to Form
CT-1 X. Otherwise, the IRS may assess an “averaged”
FTD penalty. See “Averaged” FTD penalty in section 11 of
Pub. 15 for more information about “averaged” FTD
penalties. The total tax reported on Form 945-A, line M,
must match the corrected total tax (Form CT-1, line 19
(line 15 for years before 2020), combined with any
correction reported on Form CT-1 X, line 21) for the year,
less any previous abatements and interest-free tax
assessments.

!

CAUTION

Is There a Deadline for Filing Form
CT-1 X?
Generally, you may correct overreported taxes on a
previously filed Form CT-1 if you file Form CT-1 X within 3
years of the date Form CT-1 was filed or 2 years from the
date you paid the tax reported on Form CT-1, whichever is
later. You may correct underreported taxes on a
previously filed Form CT-1 if you file Form CT-1 X within 3
years of the date the Form CT-1 was filed. We call each of
these time frames a “period of limitations.” For purposes
of the period of limitations, Form CT-1 is considered filed
on the last day in February of the succeeding year if filed
before that date.

Example—You owe tax. On March 9, 2021, you
discovered that you underreported $1,000 of RRTA
compensation on your 2020 Form CT-1. File Form CT-1 X
and pay the amount you owe by February 28, 2022,
because you discovered the error in 2021, and February
28, 2022, is the due date for that year. If you file Form
CT-1 X before February 28, 2022, pay the amount you
owe by the time you file.

Example. You filed your 2018 Form CT-1 on January
29, 2019, and payments were timely made. The IRS treats
the return as if it were filed on February 28, 2019. On
January 11, 2022, you discover that you overreported
RRTA compensation on that form by $10,000. To correct
the error, you must file Form CT-1 X by February 28,
2022, which is the end of the period of limitations, and use
the claim process.

Form CT-1 X can’t be used to correct
underreported amounts of Tier 1 Employee
CAUTION Additional Medicare Tax unless the amounts were
withheld from employee compensation.

!

Instructions for Form CT-1 X (Rev. 3-2021)

You may not file a refund claim to correct Tier 1
Employee Additional Medicare Tax actually
withheld from employees.

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discovered an error here. Report any subsequent dates
and related errors on line 35.

If you file Form CT-1 X to correct overreported tax
amounts in the last 90 days of a period of
CAUTION limitations, you must use the claim process. You
can’t use the adjustment process. If you also are
correcting underreported tax amounts, you must file
another Form CT-1 X to correct the underreported tax
amounts using the adjustment process and pay any tax
due.

!

Must You Make an Entry on Each Line?

Where Should You File Form CT-1 X?

You must provide all of the information requested at the
top of page 1 of Form CT-1 X. You must check one box
(but not both) in Part 1. In Part 2, you must check the box
on line 3 and any applicable boxes on lines 4 and 5. In
Part 3, if any line doesn’t apply, leave it blank. Complete
Parts 4 and 5 as instructed.

Send your completed Form CT-1 X to:

How Should You Report Negative Amounts?

Form CT-1 X uses negative numbers to show reductions
in tax (credits) and positive numbers to show additional
tax (amounts you owe).

Department of the Treasury
Internal Revenue Service Center
Cincinnati, OH 45999-0007

When reporting a negative amount in columns 3 and 4,
use a minus sign instead of parentheses. For example,
enter “-10.59” instead of “(10.59).” However, if you’re
completing the return on your computer and your software
only allows you to use parentheses to report negative
amounts, you may use them.

PDSs can’t deliver to P.O. boxes. You must use the U.S.
Postal Service (USPS) to mail an item to a P.O. box
address. Go to IRS.gov/PDS for the current list of PDSs. If
you file Form CT-1 X using a PDS, send it to the following
address.
Ogden-Internal Revenue Submission Processing
Center
1973 Rulon White Blvd.
Ogden, UT 84201

How Should You Make Entries on Form CT-1 X?

You can help the IRS process Form CT-1 X timely and
accurately if you follow these guidelines.
• Type or print your entries.
• Use Courier font (if possible) for all typed or
computer-generated entries.
• Omit dollar signs. You may use commas and decimal
points, if desired. Enter dollar amounts to the left of any
preprinted decimal point and cents to the right of it.
• Always show an amount for cents, even if it is zero.
Don’t round entries to whole dollars.
• Complete all four pages and sign Form CT-1 X on
page 4.
• Staple multiple sheets in the upper-left corner.

Use this address even though Form CT-1 X mailed by the
USPS goes to Cincinnati.

How Should You Complete Form CT-1
X?
Use a Separate Form CT-1 X for Each Year
You’re Correcting

Use a separate Form CT-1 X for each Form CT-1 that
you’re correcting. For example, if you found errors on your
Forms CT-1 for 2019 and 2020, file one Form CT-1 X to
correct the 2019 Form CT-1. File a second Form CT-1 X
to correct the 2020 Form CT-1.

What About Penalties and Interest?

Generally, your correction of an underreported amount
won’t be subject to an FTP penalty, FTD penalty, or
interest if you:
• File on time (by the due date of the year in which you
discover the error),
• Pay the amount shown on line 26 by the time you file
Form CT-1 X,
• Enter the date you discovered the error, and
• Explain in detail the grounds and facts relied on to
support the correction.

Employer Identification Number (EIN), RRB
Number, Name, and Address

Enter your EIN, RRB number, name, and address in the
spaces provided. Also enter your name and EIN on the
top of pages 2, 3, and 4, and on any attachments. If your
address has changed since you filed your Form CT-1,
enter the corrected information and the IRS will update
your address of record. Be sure to write your name, EIN,
“Form CT-1 X,” and the calendar year you’re correcting on
the top of any attachments.

No correction will be eligible for interest-free treatment
if any of the following apply.
• The underreported amounts relate to an issue that was
raised in an examination of a prior period.
• You knowingly underreported your employment tax
liability.
• You received a notice and demand for payment.
• You received a notice of determination under section
7436.

Return You’re Correcting

Enter the calendar year of the Form CT-1 you’re
correcting in the box at the top of page 1. Enter the same
calendar year on pages 2, 3, and 4.

Enter the Date You Discovered Errors

If you receive a notice about a penalty after you file this
return, reply to the notice with an explanation and we will
determine if you meet reasonable-cause criteria. Don’t
attach an explanation when you file your return.

You must enter the date you discovered errors. You
discover an error when you have enough information to be
able to correct it. If you’re reporting several errors that you
discovered at different times, enter the earliest date you
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Instructions for Form CT-1 X (Rev. 3-2021)

Overview of the Process

you overreported a tax amount. If you overreported an
employment tax credit or Tier 1 tax deferral, treat it like
you underreported a tax amount. If you're filing Form CT-1
X to adjust only an employment tax credit and/or Tier 1 tax
deferral and you're not correcting any overreported taxes
on Form CT-1 X, lines 6–17, skip lines 4 and 5.

To correct a previously filed Form CT-1, use Form CT-1 X
to file either an adjusted railroad retirement tax return or a
claim for refund or abatement. The adjustment process
and the claim process are outlined below.
If you underreported the tax. If you underreported
the tax on a previously filed Form CT-1, check the box on
line 1 and pay any additional amount you owe by the
time you file Form CT-1 X. For details on how to make a
payment, see the instructions for line 26, later.

1. Adjusted Railroad Retirement Tax Return

Check the box on line 1 if you’re correcting underreported
tax amounts or overreported tax amounts and you would
like to use the adjustment process to correct the errors.

Example—You underreported RRTA taxes. On
June 23, 2021, you discovered an error that results in
additional tax on your 2020 Form CT-1. File Form CT-1 X
by February 28, 2022, and pay the amount you owe by the
time you file. See When Should You File Form CT-1 X,
earlier. Don’t attach Form CT-1 X to your 2021 Form
CT-1.
If you overreported the tax. If you overreported the
tax on a previously filed Form CT-1, choose one of the
following options.
• Use the adjustment process. Check the box on line 1 to
apply any credit (negative amount) from line 26 to Form
CT-1 for the year during which you file Form CT-1 X.
• Use the claim process. Check the box on line 2 to file a
claim on Form CT-1 X requesting a refund or abatement
of the amount shown on line 26.

If you’re correcting both underreported tax amounts
and overreported tax amounts on this form, you must
check this box. If you check this box, any negative amount
shown on line 26 will be applied as a credit (tax deposit) to
your Form CT-1 for the year in which you’re filing this
form. See Example—You want your overreported tax
applied as a credit on Form CT-1, earlier.
Form CT-1 X can’t be used to correct
overreported amounts of Tier 1 Employee
CAUTION Additional Medicare Tax unless the amounts
weren’t withheld from employee compensation.

!

If you owe tax. Pay the amount shown on line 26 by the
time you file Form CT-1 X. Generally, you won’t be
charged interest if you file on time, pay on time, enter the
date you discovered the error, and explain the correction
on line 35.

To ensure that the IRS has enough time to

TIP process a credit for an overreporting tax

If you have a credit. You overreported RRTA taxes (you
have a negative amount on line 26) and want the IRS to
apply the credit to Form CT-1 for the period during which
you filed Form CT-1 X. The IRS will apply your credit on
the first day of the Form CT-1 year during which you filed
Form CT-1 X. However, the credit you show on Form
CT-1 X, line 26, may not be fully available on your Form
CT-1 if the IRS corrects it during processing or you owe
other taxes, penalties, or interest. The IRS will notify you if
your claimed credit changes or if the amount available as
a credit on Form CT-1 was reduced because of unpaid
taxes, penalties, or interest.

adjustment in the year during which you file Form
CT-1 X, you’re encouraged to file Form CT-1 X correcting
the overreported tax amount in the first 11 months of a
year. For example, if you discover an overreported tax
amount in December, you may want to file Form CT-1 X in
the first 11 months of the next year. However, there must
be 90 days remaining on the period of limitations when
you file Form CT-1 X. See the Caution under Is There a
Deadline for Filing Form CT-1 X, earlier. This should
ensure that the IRS will have enough time to process the
Form CT-1 X so that the credit will be posted before you
file Form CT-1, thus avoiding an erroneous balance due
notice from the IRS. See the example next.

Don’t check the box on line 1 if you’re correcting
overreported tax amounts and the period of
CAUTION limitations on credit or refund for Form CT-1 will
expire within 90 days of the date you file Form CT-1 X.
Instead, check the box on line 2. See Is There a Deadline
for Filing Form CT-1 X, earlier.

!

Example—You want your overreported tax applied
as a credit on Form CT-1. On December 18, 2021, you
discover you overreported your tax on your 2020 Form
CT-1 and want to choose the adjustment process. To
allow the IRS enough time to process the credit, you file
Form CT-1 X on March 8, 2022, and take the credit on
your 2022 Form CT-1.

2. Claim

Check the box on line 2 to use the claim process if you’re
correcting overreported tax amounts only and you’re
claiming a refund or abatement for the negative amount
(credit) shown on line 26. Don’t check this box if you’re
correcting any underreported tax amounts on this form.

Specific Instructions
Part 1: Select ONLY One Process
Because Form CT-1 X may be used to file either an
adjusted railroad retirement tax return or a claim for refund
or abatement, you must check one box on either line 1 or
line 2. Don’t check both boxes.

You must check the box on line 2 if you have a credit (a
negative amount on line 26) and the period of limitations
on credit or refund for Form CT-1 will expire within 90
days of the date you file Form CT-1 X. See Is There a
Deadline for Filing Form CT-1 X, earlier.

Correcting an employment tax credit or Tier 1 tax deferral. For boxes 1 and 2, if you underreported an
employment tax credit or Tier 1 tax deferral, treat it like
Instructions for Form CT-1 X (Rev. 3-2021)

The IRS usually processes claims shortly after they are
filed. The IRS will notify you if your claim is denied,
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employees, check all applicable boxes. Provide a
summary on line 35 of the amount of the corrections for
both the employees who provided written statements and
for those who didn’t.

accepted as filed, or selected to be examined. See Pub.
556, Examination of Returns, Appeal Rights, and Claims
for Refund, for more information.
Unless the IRS corrects Form CT-1 X during
processing or you owe other taxes, penalties, or interest,
the IRS will refund the amount shown on line 26, plus any
interest that applies.

!

CAUTION

You may not use Form CT-1 X to correct
overreported amounts of Tier 1 Employee
CAUTION Additional Medicare Tax unless the amounts
weren’t withheld from employee compensation.

!

You may not file a refund claim to correct Tier 1
Employee Additional Medicare Tax actually
withheld from employees.

4a. Check the box on line 4a if your overreported amount
includes each affected employee share of overcollected
Employee RRTA taxes. You’re certifying that you repaid
or reimbursed the prior year Employee RRTA taxes and
you received written statements from the employees
stating that they didn’t and won’t receive a refund or credit
for the prior year taxes. Don’t send these statements to
the IRS. Keep them for your records. Generally, all
employment tax records must be kept for at least 4 years.
Copies must be submitted to the IRS if requested.

Part 2: Complete the Certifications
You must complete all certifications that apply by
checking the appropriate boxes. If all of your corrections
relate to underreported tax amounts, complete line 3 only;
skip lines 4 and 5 and go to Part 3.
If your corrections relate to overreported tax amounts,
other than corrections related to underreported
employment tax credits and Tier 1 tax deferrals, you have
a duty to ensure that your employees' rights to recover
overpaid Employee RRTA taxes that you withheld are
protected. The certifications on lines 4 and 5 address the
requirement to:

4b. Check the box on line 4b to certify that your
overreported amount is only for Employer RRTA taxes on
those employees whom you were unable to find or those
who didn’t give you a statement described on line 4a.
4c. Check the box on line 4c to certify that your
overreported amount is only for RRTA taxes and/or Tier 1
Employee Additional Medicare Tax that you didn’t
withhold from your employees.

• Repay or reimburse your employees for the
overcollection of Employee RRTA taxes, or
• Obtain consents from your employees to file a claim on
their behalf. See Rev. Proc. 2017-28 for guidance on the
requirements for both a request for employee consent and
for the employee consent.
For purposes of these certifications, Employee RRTA
taxes consist of Tier 1 Employee tax, Tier 1 Employee
Medicare tax, and Tier 2 Employee tax. Employer RRTA
taxes consist of Tier 1 Employer tax, Tier 1 Employer
Medicare tax, and Tier 2 Employer tax.

5. Certifying Claims

If you’re filing a claim for refund or abatement of
overreported RRTA tax and/or Tier 1 Employee Additional
Medicare Tax and checked the box on line 2, check the
appropriate box on line 5. You may need to check more
than one box. If you obtained written statements or
consents from some employees but you couldn’t locate
employees or secure the statements of the remaining
employees, check all applicable boxes. Provide a
summary on line 35 of the amount of the corrections for
the employees who provided statements or consents and
those who didn’t.

3. Filing Forms W-2 or Forms W-2c

Check the box on line 3 to certify that you filed or will file
Forms W-2 or Forms W-2c with the SSA, as required,
showing your employees' correct wage and tax amounts.
See the General Instructions for Forms W-2 and W-3 for
detailed information about filing requirements.

You may not file a refund claim to correct Tier 1
Employee Additional Medicare Tax actually
CAUTION withheld from employees. If you request their
consent to file a claim for employee RRTA taxes you must
tell your employees that you can’t claim a refund of any
Tier 1 Employee Additional Medicare Tax on their behalf.
See Rev. Proc. 2017-28 for sample language to use in
your request.

!

You must check the box on line 3 to certify that you filed
Forms W-2 or Forms W-2c even if your corrections on
Form CT-1 X don’t change amounts shown on those
forms. For example, if your only correction to Form CT-1
involves misstated tax adjustments, which don’t change
the amounts reported on your employee’s Form W-2 (see
the instructions for line 18, later), check the box on line 3
to certify that you already filed all required Forms W-2 and
W-2c with the SSA. In this situation, you’re certifying that
you don’t need to file Form W-2c because you already
filed a correct Form W-2.

5a. Check the box on line 5a if your overreported tax
includes overcollected Employee RRTA taxes for each
affected employee. You’re certifying that you repaid or
reimbursed to the employees their share of the prior year
Employee RRTA taxes and you received written
statements from those employees stating that they didn’t
and won’t receive a refund or credit for the prior year
taxes. Don’t send these statements to the IRS. Keep them
for you records. Generally, all employment tax records
must be kept for at least 4 years. Copies must be
submitted to the IRS if requested.

4. Certifying Overreporting Adjustments

If you overreported RRTA tax and/or Tier 1 Employee
Additional Medicare Tax and checked the box on line 1,
check the appropriate box on line 4. You may need to
check more than one box. If you obtained written
statements from some employees but you couldn’t locate
employees or secure the statements of the remaining
-6-

Instructions for Form CT-1 X (Rev. 3-2021)

If a correction that you report in column 4 includes both
underreported and overreported amounts (see the
instructions for line 33, later), provide details for each error
on line 35.

5b. Check the box on line 5b if your overreported tax
includes overcollected prior year Employee RRTA taxes
for each affected employee and you haven’t yet repaid or
reimbursed the Employee RRTA taxes. You’re certifying
that you received consent from each affected employee to
file a claim on the employee share of those taxes and you
received written statements from those employees stating
that they didn’t and won’t receive a refund or credit for the
prior year taxes.
An employee consent must:
• Contain the name, address, and social security number
(or truncated taxpayer identification number, when
appropriate) of the employee;
• Contain the name, address, and EIN of the employer;
• Contain the tax period(s), type of tax, and the amount of
tax for which the consent is provided;
• Affirmatively state that the employee authorizes the
employer to claim a refund for the overpayment of the
employee share of tax;
• Include the employee's written statement certifying that
the employee hasn't made any previous claims (or the
claims were rejected) and won't make any future claims
for refund or credit of the amount of the overcollection;
• Identify the basis of the claim; and
• Be dated and contain the employee's signature under
penalties of perjury. The penalties of perjury statement
should be located immediately above the required
signature.
Don’t send these statements and consents to the IRS.
Keep them for your records. Generally, all employment
tax records must be kept for at least 4 years. Copies must
be submitted to the IRS if requested.
In certain situations, you may not have repaid or
reimbursed your employees or obtained their consents
prior to filing a claim, such as in cases where the period of
limitations on credit or refund is about to expire. In those
situations, file Form CT-1 X but don’t check a box on
line 5. Tell us on line 35 that you haven’t repaid or
reimbursed employees or obtained consents at the time
you file the claim. However, you must repay or reimburse
your employees and certify that you have done so before
the IRS can allow the claim.

Because special circumstances apply for lines 18–20,
22–25, and 27–32, read the instructions for each line
carefully before entering amounts in the columns.
If any line doesn’t apply to you, leave it blank.
If you previously adjusted or amended Form CT-1
using Form CT-1 X, or because of an IRS
CAUTION examination change, show amounts in column 2
that include those previously reported corrections.

!

6. Tier 1 Employer Tax—Compensation
For purposes of these instructions, all references

TIP to “sick pay” mean ordinary sick pay, not “qualified
sick leave compensation.”

If you’re correcting the compensation (other than tips and
sick pay) for the Tier 1 Employer tax you reported on Form
CT-1, line 1, enter the total corrected amount for all
employees in column 1. In column 2, enter the amount
you originally reported or as previously corrected. In
column 3, enter the difference between columns 1 and 2.
If you (or the IRS) previously corrected the amount
reported on Form CT-1, line 1, enter in column 2 the
amount after any previous corrections.
line 6 (column 1)
- line 6 (column 2)
line 6 (column 3)

If the amount in column 2 is larger than
the amount in column 1, use a minus
sign in column 3.

Multiply the amount in column 3 by 0.062 (6.2% tax
rate) and enter the result in column 4.
line 6 (column 3)
x
0.062
line 6 (column 4)

5c. Check the box on line 5c to certify that your
overreported tax is only for the Employer RRTA taxes.
This applies when affected employees didn’t give you
consent to file a claim for refund for the Employee RRTA
taxes, they couldn’t be found, or they didn’t give you a
statement described on line 5b.

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Example—Tier 1 Employer compensation
decreased. You reported $9,000 as Tier 1 Employer
compensation in computing the tax on line 1 of your 2019
Form CT-1. In December 2020, you discovered that you
included $2,000 in compensation for one of your
employees twice. To correct the error, figure the
difference on Form CT-1 X as shown.

5d. Check the box on line 5d to certify that your
overreported amount is only for RRTA taxes and/or Tier 1
Employee Additional Medicare Tax that you didn’t
withhold from your employees.

Part 3: Enter the Corrections for the
Calendar Year You’re Correcting

Column 1 (corrected amount)
Column 2 (Form CT-1, line 1)

7,000.00
- 9,000.00

Column 3 (difference)

-2,000.00

What Amounts Should You Report in Part 3?

On lines 6–17, columns 1 and 2, show amounts for all of
your employees, not just for those employees whose
amounts you’re correcting.
Instructions for Form CT-1 X (Rev. 3-2021)

Use the difference in column 3 to determine your tax
correction.

-7-

Column 3 (difference)
Tax rate (6.2%)

corrected. In column 3, enter the difference between
columns 1 and 2.

-2,000.00
x 0.062

Column 4 (tax correction)

-124.00

line 8 (column 1)
- line 8 (column 2)

Be sure to explain the reasons for this correction on
line 35.

line 8 (column 3)

7. Tier 1 Employer Medicare
Tax—Compensation

Multiply the amount in column 3 by the rate stated on
line 3 of the Form CT-1 for the year that you’re
correcting and enter the result in column 4. If the amount
in column 3 used a minus sign, also use a minus sign in
column 4.

If you’re correcting the compensation (other than tips and
sick pay) for the Tier 1 Employer Medicare tax you
reported on Form CT-1, line 2, enter the total corrected
amount in column 1. In column 2, enter the amount you
originally reported or as previously corrected. In column 3,
enter the difference between columns 1 and 2.

Example—Tier 2 Employer compensation
decreased. Following Example—Tier 1 Employer
compensation decreased in the instructions for line 6, the
compensation that you counted twice was also Tier 2
Employer compensation. Because you’re correcting your
2019 Form CT-1 in this example, use the rate from line 3
(13.1%) shown on that return. To correct the error, figure
the difference on Form CT-1 X as shown.

line 7 (column 1)
- line 7 (column 2)
line 7 (column 3)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

Multiply the amount in column 3 by 0.0145 (1.45% tax
rate) and enter the result in column 4.
line 7 (column 3)
x 0.0145
line 7 (column 4)

Column 3 (difference)

-2,000.00

Column 4 (tax correction)

Column 3 (difference)

-2,000.00

Column 4 (tax correction)

-2,000.00
x 0.131
-262.00

Be sure to explain the reasons for this correction on
line 35.

9. Tier 1 Employee Tax—Compensation

If you’re correcting the compensation, including tips
reported, but excluding sick pay, for the Tier 1 Employee
tax you reported on Form CT-1, line 4, enter the total
corrected amount in column 1. In column 2, enter the
amount you originally reported or as previously corrected.
In column 3, enter the difference between columns 1 and
2.

Use the difference in column 3 to determine your tax
correction.
Column 3 (difference)
Tax rate (1.45%)

7,000.00
- 9,000.00

Column 3 (difference)
Tax rate (13.1%)

Example—Tier 1 Employer Medicare
compensation decreased. Following Example—Tier 1
Employer compensation decreased in the instructions for
line 6, the compensation that you counted twice was also
Tier 1 Employer Medicare compensation. To correct the
error, figure the difference on Form CT-1 X as shown.
7,000.00
- 9,000.00

Column 1 (corrected amount)
Column 2 (Form CT-1, line 3)

Use the difference in column 3 to determine your tax
correction.

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Column 1 (corrected amount)
Column 2 (Form CT-1, line 2)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

-2,000.00
x 0.0145

line 9 (column 1)
- line 9 (column 2)

-29.00

line 9 (column 3)

Be sure to explain the reasons for this correction on
line 35.

8. Tier 2 Employer Tax—Compensation

If the amount in column 2 is larger than
the amount in column 1, use a minus
sign in column 3.

Multiply the amount in column 3 by 0.062 (6.2% tax
rate) and report the result in column 4.

If you’re correcting the compensation (other than tips) for
the Tier 2 Employer tax you reported on Form CT-1, line 3,
enter the total corrected amount in column 1. In column 2,
enter the amount you originally reported or as previously
-8-

Instructions for Form CT-1 X (Rev. 3-2021)

line 9 (column 3)
x 0.062
line 9 (column 4)

line 11 (column 1)
- line 11 (column 2)
If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

line 11 (column 3)

Be sure to explain the reasons for this correction on
line 35.

Multiply the amount in column 3 by 0.009 (0.9% tax
rate) and enter the result in column 4.

10. Tier 1 Employee Medicare
Tax—Compensation

line 11 (column 3)
x 0.009

If you’re correcting the compensation, including tips
reported, but excluding sick pay, for the Tier 1 Employee
Medicare tax you reported on Form CT-1, line 5, enter the
total corrected amount in column 1. In column 2, enter the
amount you originally reported or as previously corrected.
In column 3, enter the difference between columns 1 and
2.

line 11 (column 4)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

Multiply the amount in column 3 by 0.0145 (1.45% tax
rate) and enter the result in column 4.
line 10 (column 3)
x 0.0145
line 10 (column 4)

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Column 1 (corrected amount)
Column 2 (Form CT-1, line 6
(Compensation column))
Column 3 (difference)

Be sure to explain the reasons for this correction on
line 35.

11. Tier 1 Employee Additional Medicare
Tax—Compensation (Other Than Sick Pay)

30,000.00
- 3,000.00
27,000.00

Use the difference in column 3 to determine your tax
correction.

You may use Form CT-1 X to correct errors to Tier 1
Employee Additional Medicare Tax withholding for prior
years if the amount reported on Form CT-1, line 6, isn’t the
amount you actually withheld. This type of error is an
administrative error. The administrative error adjustment
corrects the amount reported on Form CT-1 to agree with
the amount actually withheld from employees.

Column 3 (difference)
Tax rate (0.9%)
Column 4 (tax correction)

27,000.00
x 0.009
243.00

Be sure to explain the reasons for this correction on
line 35.

If a prior year error was a nonadministrative error, you
may correct only the compensation subject to Tier 1
Employee Additional Medicare Tax withholding that was
originally reported on Form CT-1, line 6, or previously
corrected on Form CT-1 X. You can’t correct the tax
reported on Form CT-1, line 6.

Prior year nonadministrative errors. You may correct
only the compensation subject to Tier 1 Employee
Additional Medicare Tax withholding that you reported on
Form CT-1, line 6 (Compensation column). Enter the total
corrected amount in column 1. In column 2, enter the
amount you originally reported or as previously corrected.
In column 3, enter the difference between columns 1 and
2.

Prior year administrative error. If you’re correcting the
compensation subject to Tier 1 Employee Additional
Medicare Tax withholding that you reported on Form
CT-1, line 6, enter the total corrected amount in column 1.
In column 2, enter the amount you originally reported or as
previously corrected. In column 3, enter the difference
between columns 1 and 2.
Instructions for Form CT-1 X (Rev. 3-2021)

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Example—Prior year administrative error
(incorrectly reported amount of Tier 1 Employee
Additional Medicare Tax actually withheld). Nathan
Smith's compensation exceeded the $200,000
withholding threshold for Tier 1 Employee Additional
Medicare Tax in November 2020. The total compensation
paid to Nathan for 2020 was $230,000. You withheld $270
($30,000 x 0.009) from Nathan's compensation. However,
on your 2020 Form CT-1 you mistakenly reported $3,000
on line 6 (Compensation column), and Tier 1 Employee
Additional Medicare Tax withheld of $27 on line 6 (Tax
column). You discover the error on March 16, 2021. This
is an example of an administrative error that may be
corrected in a later calendar year because the amount
actually withheld differs from the amount reported on your
2020 Form CT-1. Use Form CT-1 X, line 11, to correct the
error as shown below.

line 10 (column 1)
- line 10 (column 2)
line 10 (column 3)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

-9-

line 11 (column 1)
- line 11 (column 2)
line 11 (column 3)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

and didn’t report Leah's $20,000 in compensation subject
to Tier 1 Employee Additional Medicare Tax withholding
on line 6 of your 2020 Form CT-1.
You discover both errors on March 16, 2021. Use Form
CT-1 X, line 11, to correct the errors as shown below.
Column 1 (corrected amount)
Column 2 (Form CT-1, line 6
(Compensation column))
Column 3 (difference)

Don’t multiply the amount in column 3 by 0.009 (0.9%
tax rate). Leave column 4 blank and explain the reasons
for this correction on line 35.
Example—Prior year nonadministrative error
(failure to withhold Tier 1 Employee Additional
Medicare Tax when required). Leah Green's
compensation exceeded the $200,000 withholding
threshold for Tier 1 Employee Additional Medicare Tax in
December 2020. The total compensation paid to Leah for
2020 was $220,000. You were required to withhold $180
($20,000 x 0.009) but you withheld nothing and didn’t
report an amount on line 6 of your 2020 Form CT-1. You
discover the error on March 16, 2021. File Form CT-1 X to
correct the compensation subject to Tier 1 Employee
Additional Medicare Tax withholding for your 2020 Form
CT-1, but you may not correct the Tier 1 Employee
Additional Medicare Tax withheld (column 4) because the
error involves a previous year and the amount previously
reported for the employee represents the actual amount
withheld from the employee during 2020.
Combination of prior year administrative and nonadministrative errors. If you’re reporting both
administrative errors and nonadministrative errors for the
same prior year, enter the total corrected amount in
column 1. In column 2, enter the amount you originally
reported or as previously corrected. In column 3, enter the
difference between columns 1 and 2. However, multiply
only the amount of compensation reported in column 3
that is related to administrative errors by 0.009 (0.9% tax
rate). Don’t multiply any compensation reported in column
3 that was related to nonadministrative errors by 0.009
(0.9% tax rate). Use line 35 to explain in detail your
corrections. The explanation must include the reasons for
the corrections and a breakdown of the amount reported
in column 3 into the amounts related to administrative
errors and nonadministrative errors.
Example—Combination of prior year
administrative and nonadministrative errors. Nathan
Smith's compensation exceeded the $200,000
withholding threshold for Tier 1 Employee Additional
Medicare Tax in November 2020. The total compensation
paid to Nathan for 2020 was $230,000. You withheld $270
($30,000 x 0.009) from Nathan's compensation. However,
on your 2020 Form CT-1, you mistakenly reported $3,000
on line 6 (Compensation column), and Tier 1 Employee
Additional Medicare Tax withheld of $27 on line 6 (Tax
column). The difference in compensation subject to Tier 1
Employee Additional Medicare Tax related to this
administrative error is $27,000 ($30,000 - $3,000).
Leah Green's compensation exceeded the $200,000
withholding threshold for Tier 1 Employee Additional
Medicare Tax in December 2020. The total compensation
paid to Leah for 2020 was $220,000. You were required to
withhold $180 ($20,000 x 0.009) but you withheld nothing

50,000.00
- 3,000.00
47,000.00

Determine the portion of compensation reported in
column 3 that is related to the administrative error
($47,000 - $20,000 (nonadministrative error) = $27,000
(administrative error)). Multiply this portion of column 3 by
0.009 (0.9% tax rate) to determine your tax correction.
Difference related to administrative error
Tax rate (0.9%)
Column 4 (tax correction)

27,000.00
x 0.009
243.00

Be sure to explain the reasons for these corrections on
line 35. You must also report that $20,000 of the amount
shown in column 3 was related to the correction of a prior
year nonadministrative error and $27,000 of the amount
shown in column 3 was related to the correction of an
administrative error.

12. Tier 2 Employee Tax—Compensation

If you’re correcting the compensation, including tips
reported, for the Tier 2 Employee tax you reported on
Form CT-1, line 7, enter the total corrected amount in
column 1. In column 2, enter the amount you originally
reported or as previously corrected. In column 3, enter the
difference between columns 1 and 2.
line 12 (column 1)
- line 12 (column 2)
line 12 (column 3)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

Multiply the amount in column 3 by the rate stated on
line 7 of the Form CT-1 for the year that you’re
correcting and enter the result in column 4. If the amount
in column 3 used a minus sign, also use a minus sign in
column 4.
Example—Tier 2 Employee compensation
decreased. Following Example—Tier 1 Employer
compensation decreased in the instructions for line 6, the
compensation that you counted twice was also Tier 2
Employee compensation. Because you’re correcting your
2019 Form CT-1 in this example, use the rate for line 7
(4.9%) shown on that return. To correct the error, figure
the difference on Form CT-1 X as shown.

-10-

Instructions for Form CT-1 X (Rev. 3-2021)

Column 1 (corrected amount)
Column 2 (Form CT-1, line 7)

7,000.00
- 9,000.00

Column 3 (difference)
Tax rate (6.2%)

Column 3 (difference)

-2,000.00

Column 4 (tax correction)

Use the difference in column 3 to determine your tax
correction.
Column 3 (difference)
Tax rate (4.9%)

-2,000.00
x 0.049

Column 4 (tax correction)

-98.00

Be sure to explain the reasons for this correction on
line 35.

14. Tier 1 Employer Medicare Tax—Sick Pay

If you’re correcting the sick pay for the Tier 1 Employer
Medicare tax you reported on Form CT-1, line 9, enter the
total corrected amount in column 1. In column 2, enter the
amount you originally reported or as previously corrected.
In column 3, enter the difference between columns 1 and
2.

For purposes of these instructions, all references

line 14 (column 1)
- line 14 (column 2)

sick leave compensation.”

line 14 (column 3)

13. Tier 1 Employer Tax—Sick Pay

line 14 (column 3)
x 0.0145
line 14 (column 4)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

Multiply the amount in column 3 by 0.062 (6.2% tax
rate) and enter the result in column 4.
line 13 (column 3)
x 0.062
line 13 (column 4)

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Column 3 (difference)

9,000.00
- 8,000.00

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Be sure to explain the reasons for this correction on
line 35.

15. Tier 1 Employee Tax—Sick Pay

If you’re correcting the sick pay for the Tier 1 Employee
tax you reported on Form CT-1, line 10, enter the total
corrected amount in column 1. In column 2, enter the
amount you originally reported or as previously corrected.
In column 3, enter the difference between columns 1 and
2.
line 15 (column 1)
- line 15 (column 2)

Example—Tier 1 Employer sick pay increased.
You reported $8,000 as Tier 1 Employer sick pay in
computing the tax on line 8 of your 2020 Form CT-1. In
December 2021, you discover that you overlooked $1,000
in sick pay for one of your employees. To correct the error,
figure the difference on Form CT-1 X as shown.
Column 1 (corrected amount)
Column 2 (Form CT-1, line 8)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

Multiply the amount in column 3 by 0.0145 (1.45% tax
rate) and enter the result in column 4.

line 13 (column 1)
- line 13 (column 2)
line 13 (column 3)

62.00

Be sure to explain the reasons for this correction on
line 35.

TIP to “sick pay” mean ordinary sick pay, not “qualified

If you’re correcting the sick pay for the Tier 1 Employer tax
you reported on Form CT-1, line 8, enter the total
corrected amount in column 1. In column 2, enter the
amount you originally reported or as previously corrected.
In column 3, enter the difference between columns 1 and
2.

1,000.00
x 0.062

line 15 (column 3)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

Multiply the amount in column 3 by 0.062 (6.2% tax
rate) and enter the result in column 4.

1,000.00

line 15 (column 3)
x 0.062

Use the difference in column 3 to determine your tax
correction.

line 15 (column 4)

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Be sure to explain the reasons for this correction on
line 35.
Instructions for Form CT-1 X (Rev. 3-2021)

-11-

16. Tier 1 Employee Medicare Tax—Sick Pay

line 18 (column 1)
- line 18 (column 2)

If you’re correcting the sick pay for the Tier 1 Employee
Medicare tax you reported on Form CT-1, line 11, enter
the total corrected amount in column 1. In column 2, enter
the amount you originally reported or as previously
corrected. In column 3, enter the difference between
columns 1 and 2.
line 16 (column 1)
- line 16 (column 2)
line 16 (column 3)

If the amount in column 2 is larger
than the amount in column 1, use a
minus sign in column 3.

Multiply the amount in column 3 by 0.0145 (1.45% tax
rate) and enter the result in column 4.
line 16 (column 3)
x 0.0145
line 16 (column 4)

If the amount in column 3 used a minus sign,
also use a minus sign in column 4.

Be sure to explain the reasons for this correction on
line 35.

17. Tier 1 Employee Additional Medicare
Tax—Sick Pay

You may use Form CT-1 X to correct errors to Tier 1
Employee Additional Medicare Tax withholding for prior
years if the amount reported on Form CT-1, line 12, isn’t
the amount you actually withheld. This type of error is an
administrative error.
If a prior year error was a nonadministrative error, you
may correct only the sick pay subject to Tier 1 Employee
Additional Medicare Tax withholding that was originally
reported on Form CT-1, line 12, or previously corrected on
Form CT-1 X. You can’t correct the tax reported on Form
CT-1, line 12.
For more information on the types of errors that can be
corrected on line 17, see the detailed examples in the
instructions for line 11, earlier.

18. Tax Adjustments

Don’t enter an amount on line 18 unless you need to
correct any current year adjustments reported on Form
CT-1, line 14. However, if you need to correct sick pay
adjustments for prior years reported on Form CT-1,
line 14, include the corrections in the calculations of Form
CT-1 X, lines 13–17.
Enter the corrected amount for tax adjustments in
column 1. Enter the originally reported or previously
corrected current year amount from Form CT-1, line 14, in
column 2. In column 3, enter the difference between
columns 1 and 2.

line 18 (column 3)

You may need to report negative numbers in any

TIP column. Make sure that the difference you enter in

column 3 accurately represents the change to
adjustments originally reported or previously corrected on
Form CT-1, line 14.
Copy the amount in column 3 to column 4. Include any
minus sign shown in column 3.
On line 35, describe what you misreported on Form
CT-1. Tell us which current year adjustments have
changed, that is, fractions of cents; uncollected Tier 1
Employee tax, Tier 1 Employee Medicare tax, or Tier 2
Employee tax on tips; or credits for overpayments of
penalty or interest paid on tax for earlier years.
Only use line 18 to correct adjustments for
fractions of cents; uncollected Tier 1 Employee
CAUTION tax, Tier 1 Employee Medicare tax, Tier 1
Employee Additional Medicare Tax, and Tier 2 Employee
tax on tips; or credits for overpayments of penalty or
interest previously reported. File a separate Form CT-1 X
for each year being corrected.

!

19. Nonrefundable Portion of Credit for
Qualified Sick and Family Leave Compensation
Form CT-1 X and these instructions use the terms

TIP “nonrefundable” and “refundable” when

discussing credits. The term “nonrefundable”
means the portion of the credit which is limited by law to
the amount of certain Tier 1 employer taxes. The term
“refundable” means the portion of the credit which is in
excess of these taxes.
If you’re correcting the nonrefundable portion of the credit
for qualified sick and family leave compensation that you
reported on Form CT-1, line 16, enter the total corrected
amount from Worksheet 1, Step 2, line 2j, in column 1. In
column 2, enter the amount you originally reported or as
previously corrected. In column 3, enter the difference
between columns 1 and 2. For more information about the
credit for qualified sick and family leave compensation, go
to IRS.gov/PLC.
Copy the amount in column 3 to column 4. However, to
properly show the amount as a credit or balance due item,
enter a positive number in column 3 as a negative number
in column 4 or a negative number in column 3 as a
positive number in column 4.
Adjustments to the nonrefundable portion of the

TIP credit for qualified sick and family leave

compensation are reported on Form CT-1 X,
line 19, and adjustments to the refundable portion of the
credit are reported on Form CT-1 X, line 24. Adjustments
to qualified sick leave compensation and qualified family
leave compensation are reported on Form CT-1 X, lines
27 and 29, respectively. Adjustments to qualified health
plan expenses allocable to qualified sick leave
-12-

Instructions for Form CT-1 X (Rev. 3-2021)

compensation and qualified family leave compensation
are reported on Form CT-1 X, lines 28 and 30,
respectively. For corrections to a 2020 Form CT-1, the
credit for qualified sick and family leave compensation is
only available for compensation paid with respect to leave
taken after March 31, 2020, and before January 1, 2021.
Credit for any qualified sick and family leave
compensation paid in 2021 will be claimed on your 2021
Form CT-1. If you’re correcting a year beginning before
2020, don’t enter any amounts on lines 19, 24, 27, 28, 29,
and 30. If you claimed the credit for qualified sick and
family leave compensation on your original 2020 Form
CT-1, and you make any corrections on Form CT-1 X for
the year to amounts used to figure this credit, you will
need to refigure the amount of the credit using Worksheet
1, later. You will also use this worksheet to figure this
credit if you’re claiming the credit for the first time on Form
CT-1 X. For more information about the credit for qualified
sick and family leave compensation, go to IRS.gov/PLC.
Example—Nonrefundable portion of credit for
qualified sick and family leave compensation
increased. You originally reported a $1,000
nonrefundable portion of credit for qualified sick and
family leave compensation on your 2020 Form CT-1,
line 16, but later determined that you understated qualified
sick leave compensation eligible for the credit. You use
Worksheet 1 to refigure the correct nonrefundable portion
of the credit for qualified sick and family leave
compensation and you determine that the correct credit is
now $2,000. To correct the error, figure the difference on
Form CT-1 X as shown below.
Column 1 (corrected amount)
Column 2 (Form CT-1, line 16)

2,000.00
- 1,000.00

Column 3 (difference)

1,000.00

To properly show the credit increase as a reduction to
your balance, enter the positive number in column 3 as a
negative number in column 4. Here is how you would
enter the numbers on Form CT-1 X, line 19.
Column 1
(corrected
amount)
2,000.00

Column 2
(Form CT-1,
line 16)
1,000.00

Column 3
(difference)

Column 4
(tax correction)

1,000.00

-1,000.00

March 12, 2020, and before January 1, 2021, see Notice
2021-20.
Copy the amount in column 3 to column 4. However, to
properly show the amount as a credit or balance due item,
enter a positive number in column 3 as a negative number
in column 4 or a negative number in column 3 as a
positive number in column 4. For an example of how to
report amounts in columns 1–4, see the instructions for
line 19, earlier.
Be sure to explain the reasons for this correction on
line 35.
Adjustments to the nonrefundable portion of the

TIP employee retention credit are reported on Form

CT-1 X, line 20, and adjustments to the
refundable portion of the credit are reported on Form CT-1
X, line 25. Adjustments to qualified compensation for the
employee retention credit are reported on Form CT-1 X,
line 31. Adjustments to qualified health plan expenses
allocable to the employee retention credit are reported on
Form CT-1 X, line 32. For corrections to a 2020 Form
CT-1, the employee retention credit is only available for
compensation paid after March 12, 2020, and before
January 1, 2021. Credit for any employee retention credit
in 2021 will be claimed in your 2021 Form CT-1. If you’re
correcting a year beginning before 2020, don’t enter any
amounts on lines 20, 25, 31, and 32. If you claimed the
employee retention credit on your original 2020 Form
CT-1, and you make any corrections on Form CT-1 X for
the year to amounts used to figure this credit, you will
need to refigure the amount of the credit using Worksheet
1, later. You will also use this worksheet to figure this
credit if you’re claiming the credit for the first time on Form
CT-1 X. For more information about the employee
retention credit for qualified wages paid after March 12,
2020, and before January 1, 2021, see Notice 2021-20.

21. Subtotal

Combine the amounts from column 4 on lines 6–20 and
enter the result on line 21.
Example. You entered “-500.00” in column 4 of line 6,
“-100.00” in column 4 of line 7, and “1,400.00” in column 4
of line 18. Combine these amounts and enter “800.00” in
column 4 of line 21.
Line 6
Line 7
Line 18
Line 21

Be sure to explain the reasons for this correction on
line 35.

20. Nonrefundable Portion of Employee
Retention Credit

If you’re correcting the nonrefundable portion of the
employee retention credit that you reported on Form
CT-1, line 17, enter the total corrected amount from
Worksheet 1, Step 3, line 3h, in column 1. In column 2,
enter the amount you originally reported or as previously
corrected. In column 3, enter the difference between
columns 1 and 2. For more information about the
employee retention credit for qualified wages paid after

Instructions for Form CT-1 X (Rev. 3-2021)

-500.00
-100.00
+ 1,400.00
800.00

22. Deferred amount of the Tier 1 Employer Tax

Use Form CT-1 X, line 22, if you need to correct the
deferred amount of the Tier 1 Employer tax that you
reported on Form CT-1, line 21. Enter the total corrected
amount in column 1. In column 2, enter the amount you
originally reported or as previously corrected by you or the
IRS. In column 3, enter the difference between columns 1
and 2.
Copy the amount in column 3 to column 4. However,
because an increase to the deferred amount of Tier 1

-13-

IRS. In column 3, enter the difference between columns 1
and 2.

Employer tax defers the payment due, to properly show
the amount as a deferral of payment, enter a positive
number in column 3 as a negative number in column 4. A
decrease to the deferred amount of the Tier 1 Employer
tax decreases the payment you can defer and must be
shown as a balance due item; therefore, to properly show
the amount as a balance due item, enter a negative
number in column 3 as a positive number in column 4.
If you’re filing Form CT-1 X to increase the amount of
the Tier 1 Employer tax (Form CT-1 X, line 6) and Tier 1
Employer tax—Sick pay (Form CT-1 X, line 13) on
compensation paid on or after March 27, 2020, and before
January 1, 2021, so that there is an additional amount of
Tier 1 Employer tax that hasn’t yet been paid, and hasn’t
yet been deferred, then you may use Form CT-1 X to
increase the amount of the deferred Tier 1 Employer tax
originally reported on Form CT-1, line 21. If you’re filing
Form CT-1 X to decrease the amount of Tier 1 Employer
tax on compensation paid on or after March 27, 2020, and
before January 1, 2021, so that there is a decrease in the
amount of Tier 1 Employer tax that is eligible for deferral,
then you must use Form CT-1 X to decrease the amount
of the deferred Tier 1 Employer tax originally reported on
Form CT-1, line 21, if the decrease in compensation
causes the amount you originally deferred to exceed the
amount that is now eligible for deferral. Otherwise, you
may only correct the amount of the deferred Tier 1
Employer tax if the amount originally reported on Form
CT-1, line 21, isn’t the amount you actually deferred (for
example, you incorrectly reported the amount that you
actually deferred). If you already paid the correct amount
of the Tier 1 Employer tax during the payroll tax deferral
period, you may not subsequently defer the payment by
filing Form CT-1 X. See IRS.gov/ETD for more information
about the interaction of credits and the deferral of
employment tax deposits and payments.
The deferred amount of the Tier 1 Employer tax was
only available for deposits and payments due on or after
March 27, 2020, and before January 1, 2021, as well as
deposits and payments due after January 1, 2021, that
are required for compensation paid during the applicable
period. Generally, 50% of the deferred amounts must be
paid by December 31, 2021, and the other 50% must be
paid by December 31, 2022. Because both December 31,
2021, and December 31, 2022, are nonbusiness days,
payments made on the next business day will be
considered timely. Any payments or deposits you make
before December 31, 2021, are first applied against your
payment due on December 31, 2021, and then applied
against your payment due on December 31, 2022. For
more information about the deferral of employment tax
deposits and payments, including when the deferral must
be paid, go to IRS.gov/ETD.
Be sure to explain the reasons for any corrections on
line 35.

23. Deferred Amount of the Tier 1 Employee Tax

Use Form CT-1 X, line 23, if you need to correct the
deferred amount of the Tier 1 Employee tax that you
reported on Form CT-1, line 22. Enter the total corrected
amount in column 1. In column 2, enter the amount you
originally reported or as previously corrected by you or the

Copy the amount in column 3 to column 4. However,
because an increase to the deferred amount of Tier 1
Employee tax defers the payment due, to properly show
the amount as a deferral of payment, enter a positive
number in column 3 as a negative number in column 4. A
decrease to the deferred amount of the Tier 1 Employee
tax decreases the payment you can defer and must be
shown as a balance due item; therefore, to properly show
the amount as a balance due item, enter a negative
number in column 3 as a positive number in column 4.
You may only correct the amount of the deferred Tier 1
Employee tax if the amount originally reported on Form
CT-1, line 22, isn’t the amount you actually deferred (for
example, you incorrectly reported the amount that you
actually deferred). If you already paid the correct amount
of the Tier 1 Employee tax, you may not subsequently
defer the payment by filing Form CT-1 X.
The deferred amount of the Tier 1 Employee tax was
only available for compensation of less than $4,000 paid
to an employee in any biweekly pay period (or the
equivalent threshold amount for other pay periods) paid
on a pay date during the period beginning on September
1, 2020, and ending on December 31, 2020. The due date
for withholding and payment of the deferred Tier 1
Employee tax is postponed until the period beginning on
January 1, 2021, and ending on December 31, 2021. The
employer is liable to pay the deferred Tier 1 Employee tax
to the IRS and must do so before January 1, 2022, to
avoid interest, penalties, and additions to tax on those
amounts. Because January 1, 2022, is a nonbusiness
day, payments made on January 3, 2022, will be
considered timely. For more information about the deferral
of employee social security tax, see Notice 2020-65 and
Notice 2021-11.
Be sure to explain the reasons for any corrections on
line 35.

24. Refundable Portion of Credit for Qualified
Sick and Family Leave Compensation

If you’re correcting the refundable portion of the credit for
qualified sick and family leave compensation that you
reported on Form CT-1, line 23, enter the total corrected
amount from Worksheet 1, Step 2, line 2k, in column 1. In
column 2, enter the amount you originally reported or as
previously corrected. In column 3, enter the difference
between columns 1 and 2. For more information about the
credit for qualified sick and family leave compensation, go
to IRS.gov/PLC.
Copy the amount in column 3 to column 4. However, to
properly show the amount as a credit or balance due item,
enter a positive number in column 3 as a negative number
in column 4 or a negative number in column 3 as a
positive number in column 4. For an example of how to
report amounts in columns 1–4, see the instructions for
line 19, earlier.
Be sure to explain the reasons for this correction on
line 35.
-14-

Instructions for Form CT-1 X (Rev. 3-2021)

25. Refundable Portion of Employee Retention
Credit

If you’re correcting the refundable portion of the employee
retention credit that you reported on Form CT-1, line 24,
enter the total corrected amount from Worksheet 1, Step
3, line 3i, in column 1. In column 2, enter the amount you
originally reported or as previously corrected. In column 3,
enter the difference between columns 1 and 2. For more
information about the employee retention credit for
qualified wages paid after March 12, 2020, and before
January 1, 2021, see Notice 2021-20.
Copy the amount in column 3 to column 4. However, to
properly show the amount as a credit or balance due item,
enter a positive number in column 3 as a negative number
in column 4 or a negative number in column 3 as a
positive number in column 4. For an example of how to
report amounts in columns 1–4, see the instructions for
line 19, earlier.
Be sure to explain the reasons for this correction on
line 35.

Corrections to Form CT-1, Line 26

Form CT-1 X doesn't include a line to correct amounts
reported on Form CT-1, line 26, for the total advances
received from filing Form(s) 7200 for the year. If a
discrepancy exists between the amount reported on Form
CT-1 and the amount of advance payments issued, the
IRS will generally correct the amount reported on Form
CT-1, line 26, to match the amount of advance payments
issued.

26. Total
Your credit. If the amount entered on line 26 is less than
zero, for example, “-115.00,” you have a credit because
you overreported your RRTA taxes.
• If you checked the box on line 1, include this amount on
Form CT-1, line 20 (“Total railroad retirement tax
deposits”) for the year during which you filed Form CT-1
X. Don’t make any changes to your Record of Railroad
Retirement Tax Liability in Part II of Form CT-1 or on Form
945-A, unless you were assessed an FTD penalty. For
more information, see the Form 945-A instructions. The
amounts reported on the record should reflect your actual
tax liability for the period.
• If you checked the box on line 2, you’re filing a claim for
refund or abatement of the amount shown.
If your credit is less than $1, we will send a refund or
apply it to your next return only if you ask us in writing to
do so.
Amount you owe. If the amount entered on line 26 is a
positive number, you must pay the amount you owe by
the time you file Form CT-1 X. You may not use any
credit that you show on another Form CT-1 X to pay the
amount you owe, even if you filed for the amount you owe
and the credit at the same time.
If you owe tax and are filing a timely Form CT-1 X, don’t
file an amended Form 945-A unless you were assessed
an FTD penalty caused by an incorrect, incomplete, or
missing Form 945-A. Don’t include the tax increase
reported on Form CT-1 X on any amended Form 945-A
you file.
Instructions for Form CT-1 X (Rev. 3-2021)

If you owe tax and are filing a late Form CT-1 X, that is,
after the due date for Form CT-1 for the period in which
you discovered the error, you must file an amended Form
945-A with the Form CT-1 X. Otherwise, the IRS may
assess an “averaged” FTD penalty. The total tax reported
on Form 945-A, line M, must match the corrected tax
(Form CT-1, line 19 (line 15 for years before 2020),
combined with any correction reported on Form CT-1 X,
line 21) for the year, less any previous abatements and
interest-free tax assessments.
Payment methods. You may pay the amount you owe
on line 26 electronically using the Electronic Federal Tax
Payment System (EFTPS) or by a check or money order.
• The preferred method of payment is EFTPS. For more
information, go to EFTPS.gov, or call EFTPS Customer
Service at 800-555-4477 or 800-733-4829 (TDD) toll free.
Additional information about EFTPS is also available in
Pub. 966.
• If you pay by check or money order, make it payable to
“United States Treasury.” On your check or money order,
be sure to write your EIN, “Form CT-1 X,” and the year
corrected.
You don’t have to pay if the amount you owe is less
than $1.

Lines 27–32

For lines 27–32, you will only enter amounts in columns 1,
2, and 3. These lines don’t have an entry space for
column 4 because these adjustments don’t directly result
in an increase or decrease to your tax. The amounts
entered on lines 27–32 are amounts that you use on
Worksheet 1 to figure the credit for qualified sick and
family leave compensation and the employee retention
credit. If you reported an incorrect amount on lines 30–35
on your original Form CT-1, then you will use lines 27–32
of Form CT-1 X to report the correction. You will also use
these lines to report amounts if you’re claiming the credit
for qualified sick and family leave compensation and/or
the employee retention credit for the first time on Form
CT-1 X. Use Worksheet 1 to refigure the credit for
qualified sick and family leave compensation and/or the
employee retention credit based on the corrected
amounts reported in column 1. Be sure to explain the
reasons for your corrections to lines 27–32 on line 35.

27. Qualified Sick Leave Compensation

If you’re correcting the qualified sick leave compensation
you reported on Form CT-1, line 30, enter the total
corrected amount for all employees in column 1. In
column 2, enter the amount you originally reported on
Form CT-1, line 30, or as previously corrected. In column
3, enter the difference between columns 1 and 2.
Qualified sick leave compensation reported on this line is
compensation (determined without regard to the
exclusions under section 3231(e)(1)) paid under the
Emergency Paid Sick Leave Act (EPSLA) as enacted
under the Families First Coronavirus Response Act
(FFCRA) and as amended by the COVID-related Tax
Relief Act of 2020 . Enter the corrected amount from
column 1 on Worksheet 1, Step 2, line 2a.

-15-

28. Qualified Health Plan Expenses Allocable to
Qualified Sick Leave Compensation

If you’re correcting the qualified health plan expenses
allocable to qualified sick leave compensation that you
reported on Form CT-1, line 31, enter the total corrected
amount for all employees in column 1. In column 2, enter
the amount you originally reported or as previously
corrected. In column 3, enter the difference between
columns 1 and 2. Enter the corrected amount from column
1 on Worksheet 1, Step 2, line 2b.

29. Qualified Family Leave Compensation

If you’re correcting the qualified family leave
compensation you reported on Form CT-1, line 32, enter
the total corrected amount for all employees in column 1.
In column 2, enter the amount you originally reported on
Form CT-1, line 32, or as previously corrected. In column
3, enter the difference between columns 1 and 2.
Qualified family leave compensation reported on this line
is compensation (determined without regard to the
exclusions under section 3231(e)(1)) paid under the
Emergency Family and Medical Leave Expansion Act as
enacted under the FFCRA and as amended by the
COVID-related Tax Relief Act of 2020. Enter the corrected
amount from column 1 on Worksheet 1, Step 2, line 2e.

30. Qualified Health Plan Expenses Allocable to
Qualified Family Leave Compensation

If you’re correcting the qualified health plan expenses
allocable to qualified family leave compensation that you
reported on Form CT-1, line 33, enter the total corrected
amount for all employees in column 1. In column 2, enter
the amount you originally reported or as previously
corrected. In column 3, enter the difference between
columns 1 and 2. Enter the corrected amount from column
1 on Worksheet 1, Step 2, line 2f.

31. Qualified Compensation for the Employee
Retention Credit

If you’re correcting the qualified compensation for the
employee retention credit that you reported on Form
CT-1, line 34, enter the total corrected amount for all
employees in column 1. In column 2, enter the amount
you originally reported or as previously corrected. In
column 3, enter the difference between columns 1 and 2.
Enter the corrected amount from column 1 on Worksheet
1, Step 3, line 3a.

32. Qualified Health Plan Expenses Allocable to
Qualified Compensation for the Employee
Retention Credit

If you’re correcting the qualified health plan expenses
allocable to qualified compensation for the employee
retention credit that you reported on Form CT-1, line 35,
enter the total corrected amount for all employees in
column 1. In column 2, enter the amount you originally
reported or as previously corrected. In column 3, enter the
difference between columns 1 and 2. Enter the corrected
amount from column 1 on Worksheet 1, Step 3, line 3b.

Part 4: Explain Your Corrections for
the Calendar Year You’re Correcting
33. Correction of Both Underreported and
Overreported Amounts

Check the box on line 33 if any corrections you entered on
lines 6–20, 22–25, or 27–32 in column 3 reflect both
underreported and overreported amounts.
Example. If you had an increase to Tier 1 Employer
compensation of $15,000 for Nathan Smith and a
decrease to Tier 1 Employer compensation of $5,000 for
Leah Green, you would enter $10,000 on line 6, column 3.
That $10,000 represents the net change resulting from
corrections.
On line 35, you must explain the reason for both the
$15,000 increase and the $5,000 decrease.

34. Did You Reclassify Any Workers?

Check the box on line 34 if you reclassified any workers to
be independent contractors or nonemployees. Also check
this box if the IRS (or you) determined that workers you
treated as independent contractors or nonemployees
should be classified as employees. On line 35, provide a
detailed reason why any worker was reclassified.
Return not filed because you didn’t treat any workers
as employees. If you didn’t previously file Form CT-1
because you mistakenly treated all workers as
independent contractors or as nonemployees, file a Form
CT-1 for each delinquent year.
Write “Misclassified Employees” in bold letters
across the top margin of page 1 of each Form CT-1.
Complete Form CT-1 using the Instructions for Form
CT-1. Attach a Form CT-1 X to each Form CT-1.
Complete the top of Form CT-1 X, including the date you
discovered the error, and provide a detailed explanation
on line 35.

35. Explain Your Corrections

Treasury regulations require you to explain in detail the
grounds and facts relied upon to support each correction.
On line 35, describe in detail each correction you entered
in column 4 on lines 6–20 and 22–25. Also use line 35 to
describe corrections made on lines 27–32. If you need
more space, attach additional sheets, but be sure to write
your name, EIN, “Form CT-1 X,” and the calendar year
you’re correcting on the top of each sheet.
You must describe the events that caused the
underreported or overreported amounts. Explanations
such as “RRTA compensation was overstated,”
“administrative/payroll errors were discovered,” or “taxes
were not withheld” are insufficient and may delay the
processing of your Form CT-1 X because the IRS may
need to ask for a more complete explanation.
Provide the following information in your explanation of
each correction.
• Form CT-1 X line number(s) affected.
• Date you discovered the error.
• Difference (amount of the error).
• Cause of the error.
-16-

Instructions for Form CT-1 X (Rev. 3-2021)

Generally, you’re not required to complete this section
if you’re filing the return as a reporting agent and have a
valid Form 8655 on file with the IRS. However, a reporting
agent must complete this section if the reporting agent
offered legal advice, for example, advising the client on
determining whether its workers are employees or
independent contractors for federal tax purposes.

You may report the information in paragraph form. The
following paragraph is an example.
“The $1,000 difference shown in column 3 of lines 6
and 7 was discovered on May 14, 2021, during an internal
payroll audit. We discovered that we included $1,000 of
compensation for one of our employees twice. This
correction removes the reported compensation that was
never paid.”

How Can You Get Forms,
Instructions, and Publications From
the IRS?

Part 5: Sign Here
You must complete all four pages of Form CT-1 X and
sign it on page 4. If you don’t sign, the processing of Form
CT-1 X will be delayed.
Who must sign the Form CT-1 X? The following
persons are authorized to sign the return for each type of
business entity.
• Sole proprietorship—The individual who owns the
business.
• Corporation (including a limited liability company
(LLC) treated as a corporation)—The president, vice
president, or other principal officer duly authorized to sign.
• Partnership (including an LLC treated as a
partnership) or unincorporated organization—A
responsible and duly authorized partner, member, or
officer having knowledge of its affairs.
• Single-member LLC treated as a disregarded entity
for federal income tax purposes—The owner of the
LLC or a principal officer duly authorized to sign.
• Trust or estate—The fiduciary.
A duly authorized agent of the taxpayer also may sign
Form CT-1 X if a valid power of attorney has been filed.
Alternative signature method. Corporate officers or
duly authorized agents may sign Form CT-1 X by rubber
stamp, mechanical device, or computer software
program. For details and required documentation, see
Rev. Proc. 2005-39, 2005-28 I.R.B. 82, available at
IRS.gov/irb/2005-28_IRB#RP-2005-39.

Paperwork Reduction Act Notice. We ask for the
information on this form to carry out the Internal Revenue
laws of the United States. You’re required to give us this
information. We need it to ensure that you’re complying
with these laws and to allow us to figure and collect the
right amount of tax.
You’re not required to provide the information
requested on a form that is subject to the Paperwork
Reduction Act unless the form displays a valid OMB
control number. Books or records relating to a form or its
instructions must be retained as long as their contents
may become material in the administration of any Internal
Revenue law. Generally, tax returns and return
information are confidential, as required by section 6103.
The time needed to complete and file Form CT-1 X will
vary depending on individual circumstances. The
estimated average time is:

Paid Preparer Use Only

Recordkeeping . . . . . . . . . . . . . . . . . . . . . . .
Learning about the law or the form . . . . . . . . .
Preparing and sending the form to the IRS . . . .

A paid preparer must sign Form CT-1 X and provide the
information in the Paid Preparer Use Only section of Part
5 if the preparer was paid to prepare Form CT-1 X and
isn’t an employee of the filing entity. Paid preparers must
sign paper returns with a manual signature. The preparer
must give the employer the return to file with the IRS and
include a copy of the return for the employer's records.
If you’re a paid preparer, write your Preparer Tax
Identification Number (PTIN) in the space provided.
Include your complete address. If you work for a firm, write
the firm's name and the EIN of the firm. You can apply for
a PTIN online or by filing Form W-12. For more
information about applying for a PTIN online, go to
IRS.gov/PTIN. You can’t use your PTIN in place of the EIN
of the tax preparation firm.

Instructions for Form CT-1 X (Rev. 3-2021)

You can download or print some of the forms and
publications you may need on IRS.gov/Forms.
Otherwise, you can go to IRS.gov/OrderForms to
place an order and have forms mailed to you. The IRS will
process your order for forms and publications as soon as
possible. Don’t resubmit requests you’ve already sent us.
You can get forms and publications faster online.

28 hr., 56 min.
53 min.
1 hr., 24 min.

If you have comments concerning the accuracy of
these time estimates or suggestions for making this form
simpler, we would be happy to hear from you. You can
send us comments from IRS.gov/FormComments. Or you
can write to the Internal Revenue Service, Tax Forms and
Publications Division, 1111 Constitution Ave. NW,
IR-6526, Washington, DC 20224. Don’t send Form CT-1
X to this address. Instead, see Where Should You File
Form CT-1 X, earlier.

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Worksheet 1. Adjusted Credit for Qualified Sick and Family Leave
Compensation and the Employee Retention Credit

Keep for Your Records

You must use this worksheet if you claimed the credit for qualified sick and family leave compensation and/or the employee retention credit on
your original Form CT-1 and you correct any amounts used to figure these credits on Form CT-1 X. You will also use this worksheet to figure
these credits if you’re claiming them for the first time on Form CT-1 X.
Step 1.

1a
1b
1c

Step 2.

2a
2a(i)
2a(ii)
2b
2c
2d
2e
2e(i)
2e(ii)
2f
2g
2h
2i
2j
2k

Step 3.

3a
3b
3c
3d
3e
3f
3g
3h
3i

Figure the Tier 1 Employer Tax
Enter the amount from Form CT-1, line 1 (Tax Column), or, if corrected, enter the
amount from Form CT-1 X, line 6, column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1a
Enter the amount from Form CT-1, line 8 (Tax Column), or, if corrected, enter the
amount from Form CT-1 X, line 13, column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1b
Tier 1 Employer tax. Add lines 1a and 1b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure the credit for qualified sick and family leave compensation
Qualified sick leave compensation reported on Form CT-1, line 30, or if corrected, the
amount from Form CT-1 X, line 27, column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enter the amount, if any, included on line 2a that is compensation excluded from the
definition of compensation under section 3231(e)(1) . . . . . . . . . . . . . . . . . . . . . . . . .
Subtract line 2a(i) from line 2a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Qualified health plan expenses allocable to qualified sick leave compensation
reported on Form CT-1, line 31, or, if corrected, Form CT-1 X, line 28,
column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tier 1 Employer Medicare tax on qualified sick leave compensation. Multiply line 2a(ii)
by 1.45% (0.0145) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Credit for qualified sick leave compensation. Add lines 2a, 2b, and 2c . . . . . . . .
Qualified family leave compensation reported on Form CT-1, line 32, or, if corrected,
the amount from Form CT-1 X, line 29, column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enter the amount, if any, included on line 2e that is compensation excluded from the
definition of compensation under section 3231(e)(1) . . . . . . . . . . . . . . . . . . . . . . . . .
Subtract line 2e(i) from line 2e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Qualified health plan expenses allocable to qualified family leave compensation
reported on Form CT-1, line 33, or, if corrected, the amount from Form CT-1 X, line 30,
column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tier 1 Employer Medicare tax on qualified family leave compensation. Multiply
line 2e(ii) by 1.45% (0.0145) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Credit for qualified family leave compensation. Add lines 2e, 2f, and 2g . . . . . . .
Credit for qualified sick and family leave compensation. Add lines 2d
and 2h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonrefundable portion of credit for qualified sick and family leave
compensation. Enter the smaller of line 1c or line 2i. Enter this amount on Form CT-1
X, line 19, column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Refundable portion of credit for qualified sick and family leave compensation.
Subtract line 2j from line 2i and enter this amount on Form CT-1 X, line 24,
column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure the employee retention credit
Qualified compensation for the employee retention credit reported on Form CT-1,
line 34, or if corrected, the amount from Form CT-1 X, line 31, column 1 . . . . . . . . . .
Qualified health plan expenses allocable to qualified compensation for the employee
retention credit reported on Form CT-1, line 35, or, if corrected, the amount from Form
CT-1 X, line 32, column 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Add lines 3a and 3b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Retention credit. Multiply line 3c by 50% (0.50) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enter the amount of the Tier 1 Employer tax from Step 1, line 1c . . . . . . . . . . . . . . . .
Enter the amount of the nonrefundable portion of the credit for qualified sick and family
leave compensation from Step 2, line 2j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subtract line 3f from line 3e. If zero or less, enter zero. . . . . . . . . . . . . . . . . . . . . . . . .
Nonrefundable portion of employee retention credit. Enter the smaller of line 3d
or line 3g. Enter this amount on Form CT-1 X, line 20, column 1 . . . . . . . . . . . . . . . . .
Refundable portion of employee retention credit. Subtract line 3h from line 3d and
enter this amount on Form CT-1 X, line 25, column 1 . . . . . . . . . . . . . . . . . . . . . . . . .

-18-

1c

2a
2a(i)
2a(ii)
2b
2c

2d

2e
2e(i)
2e(ii)
2f
2g

2h
2i
2j
2k

3a
3b
3c
3e

3d

3f
3g
3h
3i

Instructions for Form CT-1 X (Rev. 3-2021)