Contact the Bank

• When you receive a late 1099-INT form, contact the bank that sent it. Additional pieces of tax paperwork may have been mailed but not yet received. Do not proceed with correcting your return until you are certain you have all of your missing tax documents.
  
  

Recalculate Your Income

• If you receive one or more 1099-INT forms after filing your taxes, the total income you reported to the IRS was incorrect. Before you can file an amended return, you need to recalculate your income and add the amounts from the newly received documents. Once you know your new total income, you can proceed with the corrected return.
  
  

File an Amended Return

• Once you know how much additional income you need to report, the next step is to file an amended return. The IRS makes the 1040X form available to taxpayers who need to correct the amounts reported on their original tax returns. Have your original return handy, since you will need to provide some figures from it when completing the 1040X.
  
  

Proper Record Keeping

• Keeping accurate records is essential any time you deal with taxes but even more vital when you need to file an amended return. Make copies of your original tax return along with your amended return and copies of all 1099 forms and other documentation. Keep the documents in a safe place and scan them to create an electronic copy as well.