Significance

• Filing an amended return is the process by which taxpayers make adjustments to their original income tax returns. You are not usually required to complete an amended return to correct general math errors as those are usually corrected automatically by the IRS. Even though you will need your original return in order to make the calculations which you'll enter on your 1040-X, you won't need to send that original return to the IRS as the IRS already has your original return on file.
  
  

Filing

• You'll need to download form 1040X as well as any other forms, publications, or instructions at the IRS website or by calling (800) TAX-FORM. Once you have the 1040-X, enter your name and address in the first section, your filing status in Part A and the year for which you are filing the amended return in Part B. In part C, provide your reasons for filing an amended return. In the next section you'll need to decide to which category your adjustment belongs. If you are making a change to your filing status, then enter the correct amount in the appropriate lines. The numbers you are entering in these spaces are the correct amounts which you should have been entered on your original tax return.
  
  

Considerations

• If you do not have a copy of your original return with which to calculate your adjustments, then you need to complete IRS form 4506-T and mail it to the IRS to request a return transcript. The return transcript is a line by line transcript of your original return and is free of charge. The IRS will normally process your request within 30 days.
  
  

Warning

• Keep in mind that you are limited by the IRS statute of limitations with regard to how long you have to file an amended return and claim a refund. Generally, you only allowed three years from the date the return was originally filed to claim a refund, after which time you forfeit your refund and it goes into a fund named "excess collections."