Can I Fix a Mistake on a Tax Return I Already Filed?

Yes — you can correct errors on a previously filed return by filing an amended return using Form 1040-X. You generally have 3 years from the original filing deadline (or 2 years from when you paid the tax, whichever is later) to file an amended return and claim a refund. If you owe additional tax as a result of the correction, file and pay as soon as possible to minimize penalties and interest. You can now e-file amended returns for recent tax years. The IRS processes amended returns more slowly than original returns — expect 16 weeks or more for processing.