What form is used to file an amended tax return?

The correct answer is Form 1040X, which is specifically designed for filing an amended tax return. This form allows taxpayers to correct errors or make changes to their original return, such as updating income, deductions, or credits.

When a taxpayer realizes they need to change their filed tax return, it is important to use the appropriate form to ensure that the IRS can accurately process the amendments. Form 1040X includes sections for explaining the changes and clearly indicating the differences from the original return, making it a vital tool for addressing any discrepancies.

The other forms mentioned—Form 1040, Form 1040A, and Form 1040EZ—are all forms used for filing original tax returns, not for amendments. While they serve the purpose of reporting income and calculating tax liability for individual taxpayers, they do not provide the necessary structure for making adjustments to a previously filed return.