After you file

We do not know if any tax fraud has been committed.  You say the other parent has not lived there for "a couple of years."  If the IRS used the person's 2018 tax return, that may explain the address they used for the stimulus check, since they are using either 2018 or 2019 returns to issue those checks.  Would the address have been correct for a 2018 return?  And  "maybe claim head of household"---  are you the custodial parent?  Has something filed by the other parent interfered with your ability to e-file your own tax return or with claiming your children as dependents?

**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**