If he said someone else can claim him and you claimed him, and your return is being rejected, it is possible his SSN was used by someone else--even by accident. The rejection for the use of a SSN comes from the IRS---so it means somehow his SSN has been put into the system by someone. There is not a way to overcome that rejection when it happens. The only way to file your return claiming him is to print, sign, and mail your own return. Sorry.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
