How can I find out if someone else is claiming me on their tax returns, so I do not submit false information?

There is no way for you to find out if someone claimed you as a dependent on their tax return and the IRS will not tell you.

Have filed your 2022 tax return and was it rejected because your Social Security number has already been entered on a tax return received by the IRS?

Do you qualify as anyone's dependent?  If not, then they cannot claim you.  Did you submit your return and it was rejected?  If they did claim you and you do not qualify as their dependent, then you will need to select no you are not a dependent and then print and mail your return.

How old are you? If you are over 18 and not a student she cannot claim you if you earned more than $4,400 for the year.  If you are a full-time student under 24, your income can be greater than $4,400 as long as you do not provide more than half of your own support. 

 If you are living with someone else other than your mother at this point and you did not live with your mother for more than 6 months she would not be allowed to claim you. In order to claim a dependent they generally must live with you for more than 6 months out of the year. 

 Paying only your cell phone bill does not constitute paying more than half of your support.  So, again, if this is the case, she would not be able to claim you.