Non-custodial, biological parent has an FSA account for our children which was used for his portion of the child care in 2016. However, I claimed both children as dependents since I had them more than 50% of the time and all documentation shows that I paid for their expenses. His tax return was flagged because "someone else claimed childcare expenses for one of the kid's social security number and that conflicts with the 5,000 in pretax income in child care FSA he has" and he wants me to talk to my CPA on how to fix it. I believe this is his issue to fix, not mine.
edit: His argument is that the children lived with him at least 50% of the time in 2016 since we were together for 11 months of that year. However, we agreed in the beginning of that year that I would claim HoH, child care credit, etc since we both had similar incomes. I had primary custody the last month of 2016.
