Since you already filed your taxes you need to wait until your return is processed before you can amend it. Once you receive your refund you will know that it has been processed. However, do not assume that just because your check is cashed that your return has been processed. If you owe, you can pull a transcript to check to see if your return was processed.
To request either transcript online, go to www.IRS.gov and look for our new online tool, Order a Transcript. To order by phone, call 800-908-9946 and follow the prompts in the recorded message.
