945-X

Adjusted Annual Return of Withheld Federal Income Tax or Claim for Refund

Agency
IRS
Revision
Rev. February 2025
Fillable fields
50
Pages
2
Official source
IRS form page
Checked
October 21, 2026
Fill 945-X online
Page 1 of form 945-X

Form 945-X: Adjusted Annual Return of Withheld Federal Income Tax or Claim for Refund

Form 945-X is used to correct administrative errors only on a previously filed Form 945, Annual Return of Withheld Federal Income Tax. The IRS says an administrative error occurs if the federal income tax (including backup withholding) reported on Form 945 is not the amount actually withheld from payees, for example because of a mathematical or transposition error.

The form works two ways. The adjustment process corrects underreported amounts, or applies an overreported amount as a credit on Form 945. The claim process asks for a refund or abatement of overreported amounts only. One Form 945-X covers one calendar year, and the form says not to attach it to Form 945.

This page has the February 2025 revision. You can fill out the PDF free in your browser on this page and download it without an account.

What's on Form 945-X

Header

The EIN, name, trade name and address, the calendar year of the return being corrected, and the date errors were discovered.

Part 1: one process

Line 1 is the adjusted return of withheld federal income tax. Line 2 is the claim for a refund or abatement. The form says to select only one.

Part 2: corrections

Line 3 corrects federal income tax withheld (Form 945, line 1) and line 4 corrects backup withholding (Form 945, line 2), each in three columns. Line 5 totals column 3.

Part 3: explanation

Line 6 is checked when a correction includes both underreported and overreported amounts. Line 7 holds the detailed explanation of how the corrections were determined.

Part 4: signature

The signature, printed name and title, date and daytime phone, plus the Paid Preparer Use Only section.

How to fill out Form 945-X

  1. 1

    Header

    Enter the EIN, name and address, the calendar year of the Form 945 being corrected and the date errors were discovered. The instructions say to enter the earliest date when errors were found at different times.

  2. 2

    Line 1 or line 2

    Check line 1 for underreported amounts, or for overreported amounts to be credited on Form 945. Check line 2 to claim a refund or abatement of overreported amounts only. The form says not to check line 2 when correcting any underreported amount.

  3. 3

    Lines 3 and 4

    Enter the total corrected amount for all payees in column 1, the amount originally reported or as previously corrected in column 2, and the difference in column 3. The instructions say to use a minus sign for a negative difference.

  4. 4

    Line 5

    Combine column 3 of lines 3 and 4. The form says a positive amount is owed and paid when the return is filed. A negative amount is a credit on Form 945 under line 1, or the refund or abatement claimed under line 2.

  5. 5

    Lines 6 and 7

    Check line 6 if a correction mixes underreported and overreported amounts. On line 7, the instructions ask for the line numbers affected, the date the error was found, the amount and the cause of each error.

  6. 6

    Sign

    The form says to complete both pages and sign it. Enter the name, EIN and the calendar year being corrected at the top of page 2 as well.

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When and where to file Form 945-X

When to file

The instructions say to file Form 945-X when an administrative error on a previously filed Form 945 is discovered. For underreported tax, the due date is that of the return for the period in which the error was discovered (January 31 of the following year).

Time limits

The instructions say overreported tax can generally be corrected within 3 years of the date Form 945 was filed or 2 years from the date the tax was paid, whichever is later. In the last 90 days of that period, only the claim process applies.

Where to send it

The instructions list a mailing address in Cincinnati, OH or Ogden, UT by state, a P.O. box in Ogden for filers with no legal residence or principal place of business in any state, and a separate address for private delivery services.

Paying an amount owed

The instructions list EFTPS, IRS Direct Pay, credit or debit card, or a check or money order payable to "United States Treasury" with the EIN, "Form 945-X" and the year corrected written on it.

Filed separately

The form says not to attach Form 945-X to Form 945. Interest and penalties already assessed are requested back on Form 843, not on Form 945-X.

Related forms

Who files Form 945-X?

  • Payers that filed Form 945

    A filer that finds an administrative error on a previously filed Form 945 uses Form 945-X, one form for each Form 945 being corrected.

  • Not for a missing Form 945

    The instructions say that if no Form 945 was filed for a year when one should have been, Form 945-X isn't used. Form 945 is filed for each of those years instead.

  • Not for other employment returns

    The instructions say not to use Form 945-X to correct Form CT-1, 941, 943 or 944. Each of those has its own X form, such as Form 941-X or Form 944-X.

  • Not for liability-only errors

    If the only errors are in the Monthly Summary of Federal Tax Liability on Form 945 or on Form 945-A, the instructions say not to file Form 945-X and point to the Form 945-A instructions.

  • Who signs it

    The owner of a sole proprietorship, a principal officer of a corporation, a responsible partner, member or officer of a partnership, or the fiduciary of a trust or estate. A paid preparer also signs the preparer section.

Form 945-X is filed by the business or other payer that filed the Form 945 being corrected, under its employer identification number. It is not filed by the payees whose tax was withheld.

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Questions about Form 945-X

What counts as an administrative error?

The IRS says it occurs if the federal income tax (including backup withholding) reported on Form 945 is not the amount actually withheld from payees, such as a mathematical or transposition error.

Can Form 945-X fix tax that was never withheld?

The instructions give an example of a payer that failed to withhold from a new payee in a prior year and say Form 945-X can't be filed for it, because the amount reported matched what was actually withheld.

What is the difference between line 1 and line 2?

Line 1 is the adjustment process, for underreported amounts or a credit applied to Form 945. Line 2 is the claim process, for a refund or abatement of overreported amounts only. The form says to select only one.

Does Form 945-X go with Form 945?

No. The form says not to attach it to Form 945, and the instructions say to generally file it separately.

Is one Form 945-X enough for several years?

No. The form says to use a separate Form 945-X for each year that needs correction.

Who can I call for help?

The instructions list the IRS Business and Specialty Tax Line at 800-829-4933, or 800-829-4059 for TDD/TTY.