How to Amend Form 940: Steps, Deadline, and Penalties

To amend Form 940, file a complete, corrected Form 940 for the year you’re fixing, check the “Amended Return” box at the top of page 1, and attach a written statement explaining what changed and why. There is no separate “940-X” the way there is for quarterly Form 941 corrections. The IRS treats your amended filing as a replacement for the original return, so every line needs the corrected full-year figure, not just the difference.¹

What to Gather Before You Start

Pull these together before you open the form:

Your original Form 940 for the year in question. You need the baseline figures so you can see exactly what shifted.
Updated payroll records: corrected wage totals, individual employee earnings, and any reclassified workers behind the amendment.
State unemployment tax documentation, especially payment confirmations and rate notices. Errors involving the state tax credit are one of the most common reasons employers amend.
The correct year’s version of Form 940, downloaded from the IRS prior-year forms page. Rates, credit limits, and layouts change between years, and filing on the current form for an older year can cause rejection or delays.¹

Keep supporting records for at least four years from the filing date in case the IRS reviews the year.

Filling In the Corrected Return

You are completing a full Form 940 from scratch with corrected numbers, not marking up the original. Entering only the difference between old and new figures is a common mistake that creates a bigger problem than the one you started with.

Mark It Amended

At the top right of page 1, in the “Type of Return” section, check box “a” for Amended Return. If you are also a successor employer, check box “b” as well.¹ This tells the IRS to process the form as a correction rather than a duplicate original.

Rework the Numbers That Changed, and Everything They Touch

In Part 1, confirm the state or states where you paid unemployment taxes, and check the credit reduction box if it applies. In Part 2, enter corrected total wages, exempt wages, and taxable FUTA wages (the first $7,000 per employee). Line 8 multiplies taxable wages by 0.006, the 0.6% rate that applies after the standard 5.4% state credit.²

If your correction involves state unemployment tax that was paid late, Part 3 line 10 sends you to a worksheet in the instructions that recalculates the credit for late state payments. This worksheet is the whole exercise for many amendments.¹

Part 4 compares your corrected total FUTA tax against the deposits you already made and any amount you paid with the original return. Line 14 shows any balance now due; line 15 shows any overpayment, and you choose between a refund and a credit against your next return. If your total FUTA tax exceeds $500, Part 5 breaks liability out by quarter, and those figures need to match your corrected Part 2 totals.

Redo Schedule A If a Credit Reduction State Is Involved

A state becomes a credit reduction state when it borrows from the federal government to pay unemployment benefits and doesn’t repay within two years. The 5.4% FUTA credit drops by 0.3% for each year the loan remains outstanding, so your effective rate climbs to 0.9% or more.³ If you paid wages in one of those states, you complete Schedule A and attach it. When amending, make sure the corrected Schedule A wages line up with the corrected wages on the main form. A mismatch between the two triggers follow-up correspondence.

Attach a Written Explanation

Every amended Form 940 needs a written statement describing why the original was wrong and how you arrived at the new figures. Reference specific payroll periods, calculation errors, or misclassified wages. Keep it factual and short. For electronic filings, the explanation attaches as a document inside the MeF submission.¹

Sign the return in Part 7. If a paid preparer completed it, they sign their own section with their PTIN.

Where to Send the Amended Return

Paper Filing

Here’s the detail that catches employers off guard: when you mail an amended Form 940, use the “Without a payment” mailing address even if you’re enclosing a payment. The IRS instructions are explicit about this.⁴ The address itself depends on your state. Employers in the eastern half of the country generally mail to Kansas City, MO; western states mail to Ogden, UT. Tax-exempt organizations, government entities, and Indian tribal governments mail to Ogden regardless of location.⁵ Use a mailing method that gives you delivery confirmation.

Electronic Filing

Amended Forms 940 can be filed through the IRS Modernized e-File system.⁶ You e-file through IRS-approved software and sign either with an IRS-issued 94x online signature PIN or by attaching a signed Form 8453-EMP. Reporting agents can sign all electronic returns with a single PIN. Electronic filing processes faster and removes the risk of the return getting lost in the mail.

Paying a Balance Due

The IRS requires electronic payment for federal balances owed. EFTPS, IRS Direct Pay, and your IRS business tax account are all accepted. For balances of $500 or less, you can pay by credit card, debit card, or check instead. Do not send Form 940-V (the payment voucher) with an amended return.⁴

Deadline to Amend

If you’re amending to claim a refund or credit for an overpayment, you generally have three years from the return’s original due date, or three years from the date you actually filed if you filed late.⁷ Form 940 is normally due January 31 of the following year, so a 2025 return has a refund window that closes January 31, 2029. Miss it and the refund is gone.

The IRS in turn has three years to assess additional tax against you. That window extends to six years if more than 25% of gross income was left off the return, and there is no time limit at all if the return was fraudulent. The longer you wait to amend a return that under-reported tax, the more interest accrues.

Penalties and Interest If You Underpaid

If your amendment shows additional tax owed, expect a failure-to-pay penalty of 0.5% of the unpaid amount for each month or part of a month it stays outstanding, capped at 25%. On an approved IRS payment plan, the monthly rate drops to 0.25%.⁸ Interest is separate, compounds daily, and is reset quarterly. The underpayment rate for the first quarter of 2026 is 7%.⁹

You can ask for penalty abatement if you had reasonable cause. The IRS looks case by case at whether you exercised ordinary business care and prudence but still couldn’t comply. Reliance on a tax professional’s advice, a natural disaster, or inability to obtain records can qualify. Forgetfulness and general carelessness do not.¹⁰ If you plan to request abatement, include the request with your amended return rather than waiting for the penalty notice.

Check Whether Form 941 Also Needs a Correction

A wage correction on Form 940 often means your quarterly Form 941 filings for that year are wrong too. The IRS eventually notices when total wages on your 941s don’t match the corrected 940. Form 941 errors are corrected on Form 941-X, a separate adjustment form with its own rules.¹¹ One limitation to know: federal income tax withholding errors on Form 941 can generally only be corrected if you catch them in the same calendar year the wages were paid. For prior years, you’re limited to administrative errors where the amount on the 941 didn’t match what you actually withheld.

After You File

The IRS doesn’t publish a specific processing timeline for amended Forms 940. Its business return status dashboard covers Forms 1120, 941, and 1041, but not Form 940.¹² Allow several months for a paper-filed amendment. Electronic amendments tend to move faster.

If the IRS accepts the correction without questions, you’ll get a notice confirming the adjustment. If the corrected figures don’t match other records in the IRS system, expect a letter asking for supporting documentation. Overpayments come back as a refund check or as a credit toward future liabilities, depending on which box you checked on line 15. Keep the amended return, the written explanation, and the supporting records together so you can respond quickly if the IRS follows up.

1
Internal Revenue Service. Instructions for Form 940 (2025)
2
Internal Revenue Service. Topic No. 759, Form 940 – Filing and Deposit Requirements
3
Internal Revenue Service. FUTA Credit Reduction
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Internal Revenue Service. 2025 Instructions for Form 940 – Employers Annual Federal Unemployment (FUTA) Tax Return
5
Internal Revenue Service. Where to File Your Taxes for Form 940
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Internal Revenue Service. Modernized e-File (MeF) for Employment Taxes
7
Internal Revenue Service. Time IRS Can Assess Tax
8
Internal Revenue Service. Failure to Pay Penalty
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Internal Revenue Service. Quarterly Interest Rates
10
Internal Revenue Service. Reasonable Cause and Good Faith
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Internal Revenue Service. Correcting Employment Taxes
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Internal Revenue Service. Processing Status for Tax Forms