My son received a form 3531 attached to his tax return stating that he forgot to sign his 1040 tax return. He signed it but we lost the return envelope that was sent to us and we do not know where to send it. I have tried calling the IRS but was put on hold for ever after navigating through a maze of voice options. I'm sure this is a simple question but cannot find the answer anywhere.

once you call the IRS, then they ‘ d tell you to mail it back to where it came from. To be mailed to: Internal Revenue Service , Submission Processing Center, Kansas City, Mo. 64999; if you send it back to incorrect address, it’d take longer toprocess.as you resubmitt the signed return to the IRS, your refund will be processed aslongas you are subject to refund. You need to retain a copy of 3531 and resubmit it to the IRS ASAP.there is no penalty in resubmitting 3531 .