The IRS offers one way to protect your identity from people obtaining your tax refund, it called the IP PIN. All taxpayers can obtain one, even for Children. I have had several mothers, whom I filed returns to only find out their spouse already took the Child Tax Credit, so either they have to negotiate something or talk to a lawyer. One way to prevent a spouse claiming a child tax credit for a child is by obtaining an Identity Protection PIN. Please go to www.irs.gov/ippin
There are a lot of people scamming out there, so if you fear someone has obtained your social security number, get an IP PIN, then the tax professional needs both numbers to submit the return.
An IP PIN is a six-digit code that helps prevent identity thieves from filing fraudulent tax returns using your personally identifiable information