I filed my taxes last 03/2021 as Married filing separately. My ex husband filed his tax return with my name this 05/2021. We divorced last 02/2021. What should I do?

[xmasbaby0]

Well---your ex messed up.   If you were legally married at the end of 2020---and you say your divorce happened in 2021----then your filing choices for 2020 were to file married filing separately or married filing jointly.   But a joint return requires that you both agree to that---he did not have the right to file a joint return without your agreement to it.   If you already filed MFS----did you e-file?  Was the return accepted?  If so, then it would not have been possible for your ex to e-file a joint return with your SSN on it---it would be rejected.   If he mailed it, then you are both going to get letters from the IRS someday and he will have some explaining to do.

[ritzchocolate]

Thank you for quick reply. As for your question  If you already filed MFS----did you e-file? Yes. I did e-file last through Turbo Tax March 2021 and it was accepted , I have already received the refund. The reason I found out about , I received an email from Tax Act e-filing which includes my ex husbands name. I did not consent nor give him my SSN. 

[xmasbaby0]

Well----whatever he did ---- if he filed a joint return that was wrong.    When you file MFS you do have to put each other's SSN's on both returns----did you use his on your return?   Are you sure he filed joint--- maybe he filed MFS and just entered your SSN like he was supposed to.

If I am filing a separate return why do I have to list my spouse’s information on my return?

Even if you file separate returns (the worst way to file) you each have to list each other's SSN's and some other information on your own tax return.  The IRS can then cross check to make sure you are not "double dipping" for itemized deductions, dependents, etc.

If you are in a community property state, there is more information that will be needed.

Community property states:  AZ, CA, ID, LA, NV, NM, TX, WA, WI