Deductions & credits

From your original question:    " I thought I can only use one of DCFSA and child tax credit. "

The most childcare credit you are allowed to get for one child is $3000.  So the other $2000 is taxable for you.
**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.**