When Should You File Form 944-X?

File Form 944-X when you discover an error on a previously filed Form 944.

However, if your only errors on Form 944 relate to federal tax liabilities reported in Part 2 of Form 944 or on Form 945-A, Annual Record of Federal Tax Liability, don’t file Form 944-X. To correct federal tax liabilities reported in Part 2 of Form 944, file Form 945-A, but only enter the monthly totals. The daily entries aren’t required. For more information about correcting federal tax liabilities reported on Form 945-A, see the Form 945-A instructions.

Due dates. The due date for filing Form 944-X depends on when you discover an error and if you underreported or overreported tax. If you underreported tax, see Underreported tax next. 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 and Overreported tax—Claim process , later.

If any due date falls on a Saturday, Sunday, or legal holiday, you may file Form 944-X on the next business day. If we receive Form 944-X after the due date, we will treat Form 944-X as filed on time if the envelope containing Form 944-X is properly addressed, contains sufficient postage, and is postmarked by the U.S. Postal Service (USPS) 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 944-X filed when it is actually received. See Pub. 15 for more information on legal holidays. For more information about PDSs, see Where Should You File Form 944-X , later.

Underreported tax. If you’re correcting underreported tax, you must file Form 944-X by the due date of the return for the return period in which you discovered the error (January 31 of the following year) and pay the amount you owe by the time you file . Doing so will generally 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 27, later.

If Form 944-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 944-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 tax (Form 944, line 9, combined with any correction entered on Form 944-X, line 22) for the year, less any previous abatements and interest-free tax assessments.

Example—You owe tax. On February 13, 2026, you discovered that you underreported $1,000 of social security and Medicare wages on your 2025 Form 944. File Form 944-X and pay the amount you owe by February 1, 2027 (January 31, 2027, is a Sunday), because you discovered the error in 2026 and February 1, 2027, is the due date for that year. If you file Form 944-X before February 1, 2027, pay the amount you owe by the time you file.

Caution: Form 944-X can’t be used to correct underreported amounts of Additional Medicare Tax unless the amounts were withheld from employee wages.

Overreported tax—Adjustment process. If you overreported tax and choose to apply the credit on Form 944 or Form 941, file an adjusted return on Form 944-X soon after you discover the error but more than 90 days before the period of limitations on the credit or refund for Form 944 expires. See Is There a Deadline for Filing Form 944-X , later.

Caution: Form 944-X can’t be used to correct overreported amounts of Additional Medicare Tax unless the amounts were not withheld from employee wages.

Instructions for Form 944-X (Rev. 2-2026) 5

Example—You want your credit applied to Form 944. You filed your 2025 Form 944 on February 2, 2026, and payments were timely made. On May 4, 2026, you discover that you overreported tax on your 2025 Form 944. You file Form 944-X on June 5, 2026, 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, 2026. When you file your 2026 Form 944, include the amount from Form 944-X, line 27, on the “Total deposits” line of your 2026 Form 944.

Overreported tax—Claim process. If you overreported tax on Form 944, you may choose to file a claim for refund or abatement on Form 944-X any time before the period of limitations on credit or refund expires. If you also need to correct any underreported tax amounts, you must file another Form 944-X reporting only corrections to the underreported tax amounts. See Is There a Deadline for Filing Form 944-X next.

Caution: You may not file a refund claim to correct federal income tax or Additional Medicare Tax actually withheld from employees.