I have ammended my 2020 return to take my adult son off as a dependant. How long before he is able to file his return? It keeps getting rejected.

[608060cu]

His is being rejected stating that his SS

[DoninGA]

A federal amended tax return, Form 1040-X, can take 4 months or longer for the IRS to process.

He will have to print and mail his tax return since your return with his SS number as a dependent is already in the IRS databases.  

[xmasbaby0]

Since you already put his SSN into the system by claiming him, he cannot e-file this year at all.   It will do him no good to wait for you to amend.  His own return can only be filed by printing, signing and mailing it in now.  Your own amended return will take months to be processed and will never "catch up" in order for your son to e-file.

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

[NCperson]

while it wasn't mentioned 'why' the taxpayer wants to remove the adult as a dependent, note that if he lives in your home and earns less than $4300 and you provide more than 50% of his support, he CAN be your dependent.  if that is the case, he is NOT eligible for stimulus payments, even if you don't claim him.