If you mail a return that has 1099 or W-2 tax withholding and you did not physically attach a copy of the 1099-R (or other 1099) and W-2's to the mailed tax return, the IRS will simply return the unprocessed return to you along with a notice that the required attachments are missing and to attach them and re-mail the return.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
