If someone claimed you as a dependent and files first which blocks you from e-filing, you print your return, sign it, and mail it to the IRS. When the IRS discovers the conflict, they will send letters to both taxpayers asking for proof and the person who filed incorrectly may be subject to repayment of taxes with interest and possibly a penalty.
Understand that if you earn less than $4300 of taxable income, someone else could legally claim you as a dependent if they provide more than half your financial support, and if you lived in their home all year, even if they are not related to you. If you don’t need those tests, they can’t legally claim you.
If you are single, over age 25, and your income was earned by working, you should qualify for a small amount of earned income credit, which would be denied to you if someone else claimed you as a dependent. If you file a return claiming EIC after someone else claims you as a dependent, the IRS will send letters and you will provide your explanation.
