My tax return was rejected after filing with Turbotax

[irvintt]

What happened:

R0000-507-01 - A dependent on your return has already been claimed (or claimed themselves) on another return.

I have a college age son that is a dependent on my taxes this year.  When I did my taxes last year 2019, I did not claim him.  For tax year 2019, he worked the summer and filed a tax return and received a small refund.  With that filing he also received the stimulus checks.  For the summer of 2020, he did not work and will not file this tax season.  What must I do to continue with my filing as it stands; College son as a dependent on my return?

[rjs]

It looks like somebody else claimed your son as a dependent for 2020. If you are sure that he has not filed a 2020 tax return, then someone else claimed him. Maybe he did file and didn't tell you. Could his other parent, or some other relative, have claimed him?

In any case, you cannot e-file your tax return this year. You will have to print it, sign it, and file it by mail. Eventually you and the other person will get letters from the IRS to straighten out whether you are entitled to claim your son.

[irvintt]

My son does not have another parent to file and claim him. Also, he has not filed for 2020. I believe because he filed for 2019 with a status of single the IRS is flagging me because my son has filed last year and they assume he will file again.  And, he has received the new stimulus payment last week. So, he may not qualify as a dependent anymore.  I do not agree with the IRS status and I will file by mail to get a response on what's relly going on.  I need to get him properly set as one of my dependents.

[ThomasM125]

If your son can qualify as your dependent then you should claim him as such. Even if he received a stimulus check that belonged to you, you should still get the check as well.