Found a mistake on a return you already filed?

Filing the original return is not the end of the story. If something was wrong or something arrived late, Form 1040-X amends it. The most common reasons we see are a corrected or late 1099, income that got left off, a deduction or credit you qualified for and missed, a filing-status change, or a return another preparer or software got wrong.

When amending is worth it

Not every small error needs an amendment. The IRS fixes its own math and will often write to you about a missing form. Amend when the change actually moves your tax: unreported income, a credit you were entitled to, a wrong cost basis on a stock or RSU sale, or a status that should have been different. We look at whether the refund or correction is worth the filing before you spend anything.

The three-year refund window

If an amendment puts a refund in your pocket, the clock matters. You generally have three years from when you filed the original return, or two years from when you paid the tax, whichever is later. Older years can still be filed to correct the record, but the refund may be lost. If you are sitting on a year you think you overpaid, this is the part not to put off.

If you think an old return left money on the table, give us a call before that three-year window closes.

How we handle it

1. Read the original. We review the return as filed and the new document or issue that changed things.
2. Rework the numbers. We rebuild the return correctly and show you the before-and-after so you can see exactly what moved and why.
3. File and track. We file the 1040-X (and the matching state amendment if you need one) and tell you what to expect while it processes.

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Frequently asked questions

How long do I have to amend a return and still get a refund?

Generally three years from the date you filed the original return, or two years from the date you paid the tax, whichever is later. So a 2022 return filed in April 2023 is usually amendable for a refund through about April 2026. Miss that window and the refund is gone, even if the IRS owes you.

I already filed. Should I just wait for the IRS to catch the mistake?

Usually no. If you left off income, the IRS often sends a CP2000 proposing extra tax plus interest and sometimes a penalty. Filing a 1040-X yourself, with the deductions and basis the CP2000 ignores, almost always produces a better number than accepting their version.

Do I have to amend my state return too?

Often, yes. New Hampshire has no tax on wages, so there is usually nothing to amend at the state level for W-2 income. But if you also file a Massachusetts return, MA has its own amended-return process and the federal change usually flows through to it. We handle both so the numbers match.

How long does an amended return take to process?

The IRS asks for up to 16 weeks, and in practice it often runs longer. There is nothing wrong with your return when it sits in processing for months. We file it correctly, give you a copy of exactly what changed, and tell you what to expect.