Your only proof is your bank statement or credit card showing it coming out. You don't exactly pay though Turbo Tax. You put down your bank account and routing number on your return for the IRS to directly take it out of your account. Maybe the IRS had trouble taking it out of your bank account? Or you said you would mail a check and then mail a check or go to the IRS website to pay by direct debit or credit card. So if you still need to pay.... www.irs.gov/payments
