I claimed my son on my return and on his it is not asking if someone else can claim him as a dependent where would that question be at when doing taxes

[VolvoGirl]

Go to My Info 

Click Edit by his name and scroll down to #3

[AlanT]

That question would be asked at the beginning during the personal information interview.  

Since you have already filed and claimed your son, he will not be able to claim himself.  His return will be rejected.  

Please follow these instructions to make changes to his Information:

1. Login to your TurboTax Account 
2. Click "Take Me To My Return"
3. Click "My Info" from the left side of your screen
4. Scroll down to the area you wish to edit.