@Kdea89 -- I suspect that your bf's problem isn't that he claimed the kids as dependents; it's that he mistakenly filed as Head of Household. To file HOH, a taxpayer must have a qualifying child or dependent. Your kids don't qualify him to file HOH because they're not related to him. You can find a detailed explanation here:
https://turbotax.intuit.com/tax-tips/family/guide-to-filing-taxes-as-head-of-household/L4Nx6DYu9
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
