So he claimed himself as independent? Sorry you will have to print and mail your return this year. He will have to amend his. Even if he amends it won't clear his ssn from the IRS so you can't efile it again. So you don't have to wait to mail yours.
Did your son say he cannot be claimed as someone else's dependent? That is what would cause your return to be rejected if you are claiming him.
MY DEPENDENT SAID HE COULD NOT BE CLAIMED
Your dependent filed a return without saying he could be claimed on your return and your return was rejected? AFTER his return has been fully processed and he has received his refund, he has to file an amended return that says he can be claimed as a dependent on someone else’s return. Amended returns must be prepared on a Form 1040X—It takes the IRS at least four months (or more) to process an amended return.
Meanwhile, since your e-filed return has been rejected, you now have to print and mail it in to the IRS. You will not be able to e-file. You do not have to wait for your dependent’s amended return to be processed. Remember that when you mail a return, you need to include copies of your W-2, etc. with your return. Use a mailing service like certified mail that will track it so you will know that the IRS received it.
For your dependent:
Select your tax year for amending instructions: