Amending a Tax Return

• There are a number of reasons why taxpayers might need to amend a federal tax return. Those who forget to claim additional income, reported incorrect information or want to claim an additional tax credit should do so by completing Form 1040X and submitting it by the deadline.
  
  

Form 1040X

• Form 1040X includes three columns for figures: Column A, which reports the totals on the original tax return; Column B, which shows the change between the original numbers and the corrected figures; and Column C, which displays the new totals. Page 2 of the form includes a section where taxpayers can explain the reasons for amending their returns.
  
  

Completing the Form

• Taxpayers begin filling out the form by completing the address section, which is similar to the address section on Form 1040. They should then use the previous year's return to enter the original return's figures in Column A. Certain individuals may find it easier to complete Column C by reporting the necessary changes and then complete Column B by finding the difference between the original figures and the corrected totals. Taxpayers should also include documentation that supports the changes on the amended return. For example, an individual who claims additional earned income not previously reported should include the appropriate Form W-2 or 1099.
  
  

Submitting Form 1040X

• The Internal Revenue Service doesn't allow taxpayers to file Form 1040X electronically, even if they filed the original tax return electronically. Individuals must complete a paper version of Form 1040X and mail it, along with any necessary payment and supporting documents, to the appropriate IRS address. Generally, it takes the IRS eight to 12 weeks to process the amended return.