What Is the Purpose of Form 943-X?

Use Form 943-X to correct errors on a previously filed Form 943. Use Form 943-X to correct:

• Wages subject to social security tax;

• Wages subject to Medicare tax;

• Wages subject to Additional Medicare Tax withholding;

• Federal income tax withheld from wages;

• Qualified small business payroll tax credit for increasing research activities;

• Amounts reported on Form 943 for the credit for qualified sick and family leave wages for leave taken after March 31, 2020, and before April 1, 2021, including adjustments to Form 943, lines 2a, 2b, 12b, 14d, 18, and 19;

• Amounts reported on Form 943 for the credit for qualified sick and family leave wages for leave taken after March 31, 2021, and before October 1, 2021, including adjustments to Form 943, lines 12d, 14f, 22, 23, 24, 25, 26, and 27; and

• Amounts reported on Form 943 for the COBRA premium assistance credit for periods of coverage beginning on or after April 1, 2021, through periods of coverage beginning on or before September 30, 2021, including adjustments to Form 943, lines 12e, 12f, and 14g.

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 943 or 943-X.

Tip: We use the terms “correct” and “corrections” on Form 943-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

4 Instructions for Form 943-X (Rev. 2-2026)

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 .

When you discover an error on a previously filed Form 943, you must:

• Correct that error using Form 943-X;

• File a separate Form 943-X for each Form 943 that you’re correcting; and

• Generally, file Form 943-X separately. Don’t file Form 943-X with Form 943. However, if you didn’t previously file Form 943 because you mistakenly treated your employees as nonemployees, you may have to file Form 943-X with Form 943. See the instructions for line 40, later.

If you didn’t file a Form 943 for 1 or more years for which you should have filed Form 943, don’t use Form 943-X. Instead, file Form 943 for each of those years. Also, see When Should You File Form 943-X, later. However, if you didn’t file Form(s) 943 because you improperly treated workers as independent contractors or nonemployees and are now reclassifying them as employees, see the instructions for line 40, later.

Tip: Unless otherwise specified in these instructions, an underreported employment tax credit should be treated like an overreported tax amount. An overreported employment tax credit 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, later.

Report the correction of underreported and overreported tax amounts for the same year on a single Form 943-X, unless you’re requesting a refund or abatement. If you’re requesting a refund or abatement and you’re correcting both underreported and overreported tax amounts, file one Form 943-X correcting the underreported tax amounts only and a second Form 943-X correcting the overreported tax amounts.

You’ll use the adjustment process if you underreported employment taxes and are making a payment, or if you overreported employment taxes and will be applying the credit to Form 943 for the period during which you file Form 943-X. However, see the Caution under Is There a Deadline for Filing Form 943-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 employment taxes and are requesting a refund or abatement of the overreported tax amount. Follow the chart on page 6 of Form 943-X for help in choosing whether to use the adjustment process or the claim process. Be sure to give us a detailed explanation on line 41 for each correction that you show on Form 943-X.

Continue to report current-year adjustments for fractions of cents, third-party sick pay, and group-term life insurance on Form 943, line 10.

You have additional requirements to complete when filing Form 943-X, such as certifying that you filed (or will file) all applicable Forms W-2 and Forms W-2c. For corrections of overreported federal income tax, social security tax, Medicare tax, or Additional Medicare Tax,

you must make any certifications that apply to your situation.

Caution: Don’t use Form 943-X to correct Form CT-1, 941, 941-SS, 944, or 945. Instead, use the “X” form that corresponds to those forms (Form CT-1 X, 941-X, 944-X, or 945-X).