Following up,  I called EFTPS  1-888-353-4537 to check on the electronic funds withdrawal,  they were able to give me the confirmations I needed.  I hade two extension payments of several hundred thousand dollars each, and I was concerned.  Did not want to call the client because that would have been embarrassing.  I am supposed to have all the answers.  EFTPS had a 15 minute hold time.  And they required that I provide tax payer ID,  Bank account routing and account number, and the exact amount of the payment before they would confirm.   I am substantially relieved.   Good Luck Lisa