What Is an Amended Tax Return and How Do You File One?

An amended tax return serves as a formal correction to a federal income tax return that has already been filed. Its primary purpose is to rectify errors or report new financial information to the Internal Revenue Service (IRS). When a taxpayer discovers a mistake or receives updated documentation after submitting their original return, an amended return provides the necessary mechanism to update their tax records. This process ensures that the IRS has accurate financial information, reflecting the taxpayer’s true tax liability or refund entitlement.

Common Reasons for Amending

Taxpayers often amend returns due to inaccuracies or omissions in their initial filing. Errors in income reporting, such as under- or over-reporting wages, business income, or investment earnings, are a frequent cause. These discrepancies may arise from overlooked income statements or miscalculations.

Missed deductions or credits that could reduce tax liability are another common scenario. Taxpayers might forget to claim eligible deductions, such as student loan interest or contributions to an Individual Retirement Arrangement (IRA). Valuable tax credits, like the child tax credit or education credits, can also be inadvertently omitted.

Changes in filing status also necessitate an amendment. For example, a taxpayer might realize they used an incorrect status, such as filing as single when eligible for head of household. Receiving corrected tax forms (e.g., W-2 or 1099-MISC) or making adjustments related to dependents are other common reasons.

Preparing Your Amended Tax Return

Before filling out an amended tax return, gather all necessary documents to ensure accuracy. You will need your original tax return (e.g., Form 1040, 1040-SR, or 1040-NR) and all supporting documents related to the changes, such as corrected W-2 forms, new receipts, or updated brokerage statements.

For individuals, the primary form used to amend a federal income tax return is Form 1040-X, Amended U.S. Individual Income Tax Return. This form is structured with three columns: Column A for original amounts, Column B for net changes (increase or decrease), and Column C for corrected amounts.

When completing Form 1040-X, specify the tax year. Transfer original amounts to Column A. Calculate and enter the difference for each correction in Column B. Then, add or subtract Column B from Column A to get the corrected amount for Column C.

Part III of Form 1040-X requires a clear explanation for each change, helping the IRS understand your amendments. You can obtain Form 1040-X from the IRS website or through tax software. Generally, you have three years from the date you filed your original return or two years from the date you paid the tax, whichever is later, to file an amended return seeking a refund.

Filing Your Amended Tax Return

Once you have prepared Form 1040-X and gathered all supporting documentation, submit it to the IRS. While some tax software allows electronic filing for Form 1040-X for the current and two prior tax years, amended returns for most situations must be mailed. Careful attention to mailing instructions is important.

Mail your completed Form 1040-X and any new supporting documents (e.g., corrected W-2 or 1099) to the IRS address specified in the Form 1040-X instructions for your state. If responding to an IRS notice, use the address provided on that notice. Send each amended return for different tax years in separate envelopes to avoid processing delays.

If your amended return indicates you owe additional tax, you have several payment options. You can include a check or money order, payable to the “U.S. Treasury,” with your mailed Form 1040-X, ensuring it is enclosed but not attached. Alternatively, pay online via IRS Direct Pay (from checking/savings) or by debit/credit card through an authorized processor. If a refund is due, it will be issued via check or direct deposit once processed.

Retain a copy of your completed Form 1040-X and all accompanying documents for your records, ensuring a complete history of your tax filings and adjustments. Following these guidelines helps facilitate processing by the IRS.

What Happens After Filing

After submitting your amended tax return, manage expectations regarding processing times. Amended returns take longer to process than original returns, often taking 16 weeks or more. While some electronically filed amended returns might be processed faster, significant delays can occur if the return has errors, is incomplete, or requires additional review.

You can track the status of your amended return using the “Where’s My Amended Return?” tool on the IRS website. This tool checks status for the current and up to three prior tax years, updating daily. To use it, you will need your Social Security number, date of birth, and ZIP code.

The IRS may send correspondence or request additional information for questions or discrepancies. Respond promptly to any IRS notices to avoid further delays. If your amended return results in a refund, it will be issued as a check or direct deposit once processing is complete.

Conversely, if the amendment indicates you owe more tax, the IRS will send a bill. Interest may be assessed on additional tax owed from the original due date, even with an extension. Penalties might also apply for significant underpayment or failure to file or pay on time. However, the IRS typically calculates any applicable interest and penalties and includes them in the bill, rather than requiring you to calculate them on Form 1040-X.