forgot check mark "someone else can claim as a dependent

[ductamluong]

my son is a full-time student born at 2001,he had a job in Walmart and he earn total 12,011 on this 2019 .

he had live with me whole year and I almost support he for everything. He already filed a return for 2019 tax year but forgot check mark the box indicate "someone else can claim you as a dependent". Now, I need to file a return for 2019 tax year with my husband, but don't know that we can claim he as a dependent ? Please help me

[VolvoGirl]

You can claim him but if your return rejects because he claimed himself you will have to mail your return.  He will have to amend his return.

The amended return won't be ready until late February.

How to amend an Online return

https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/00/27577

[ductamluong]

thank you so much, but I have new question, because my son not answer for the questions :someone can claim you as a dependent" , he left it blank. How is IRS determined that he claim himself or not?

[ductamluong]

p/s: if I claimed him as a dependent, it will effect on him refund?

[VolvoGirl]

If he claimed himself and  you mail your return and claim him then the IRS might send you both a letter to find out who is suppose to claim him.  It may take a long time to get the letter.  

If he amends his return to say you can claim him it might change his refund if he got any credits like the EIC low income credit.  So he might have to pay some back.