Someone is claiming my kids on their taxes what should I do about finding out who is doing it.

The IRS won't tell you - tax returns are confidential, so they won't give you information from someone else's return. What you need to do is file your tax return claiming your children, if appropriate, and be prepared to defend why you are the appropriate person to claim them. You will have to file a paper return, not electronically. The IRS will investigate and determine whose tax return is the correct one for claiming them.

This has become a frequent question with the advent of electronic filing. The first return filed containing the child's SSN is accepted. Any subsequent ELECTRONIC filings will be rejected because the SSN has already been recorded. So the subsequent filer has to file manually, using a paper return. Then let the IRS sort it out.

This happens mostly with divorced or separated people. So the likelihood is it's the other parent.