If the amount deducted from your paycheck is a pre-tax deduction and you use that money to pay your childcare then the amount used from that pre-tax account for childcare expense would not be a deduction on your tax return. However, if your childcare exceeded the amount in your pre-tax account then the amount that is greater than the pre-taxed deduction would be an allowable deduction. ie: you have $5000 in your pre-tax childcare account. You use the whole $5000 to pay childcare but the total childcare expense was $7000. Then only $2000 would be allowed as a childcare deduction.