My mom claimed me as a dependent by lying, what can I do?

[johnnyrocket5]

I was finishing my taxes and when I went to file electronically, my return would not be accepted because I had been claimed as a dependent. I discovered that my mom claimed me, but, based on everything I've researched she should not have - she lied, and now I am not sure what I should do. I am 21 years old and based on the below, there's no way she should have been able to claim me:

1. I moved in with my dad and step-mom (they are divorced) in February of 2020, so I only lived with her for 2 months

2. While I was registered for school the first semester of 2020 and did attend, I dropped out and never finished - She did pay the tuition because I dropped late, but even then it was not full-time (only 9 hours)

3. I made over 10K in gross income last year - based on my research it's way over the $4300 threshold that the IRS shows

4. I didn't live with her most of the year, so she definitely didn't provide 1/2 of my support, if anything my dad and his wife did

I tried talking to her about it but she refuses to amend her taxes, claiming that because she paid for that semester of school that I dropped and that because she pays for my cell phone, she has every right to claim me as a dependent. I also believed she lied to her tax preparer and told her that I lived with her. I can prove that I didn't live with her. I filed 2019 taxes (she didn't claim me then, by the way) using my dad's address, my bank statements have my dad's address, all my paycheck stubs have my dads address. 

Based on what I read, the solution is to send my return by mail and basically wait for the IRS to trigger an audit. I'm really upset because if I let her claim me, I will lose about $1,000 in my return and the $1,400 stimulus check that's coming, and I could really use that money for school (I have loans to pay for my college).  She did the same thing to my brother, and he is going to lose about $3,400.

Is there anything else I can do? If not, would it help to attach a letter to my return letting them know the situation and detailing how she basically lied to claim me? Any input would be greatly appreciate it.

[DavidD66]

You are correct, you will have to print and mail your tax return.  It wouldn't hurt to send a letter with your return.  Once your return has been processed, the IRS will contact both of you to determine whether or not you qualify as your mother's dependent.  Based upon what you've stated, your mother will not be able to claim you.

Be aware, the IRS already has a backlog of paper returns.  During normal times, filing a paper return can delay things by weeks.  You may experience a lengthy delay.  

[Bsch4477]

You understand the situation perfectly and I congratulate you on doing the research. 
Yes, file by mail with an explanation that your mom fraudulently claimed you with the supporting information that you posted. The IRS will sort it out. If you tell your mom what you are doing and that the IRS will be involved and require her to return money with interest, possibly fines and maybe future audits, maybe she will change her mind and amend her return. 

[fanfare]

do not attach extraneous letters to your mailed tax return.

you should not have to wait for your stimulus payment because you will not be checking that box: someone can claim me.