Fill out the money order at the counter with a retail associate. Pay the dollar value of the money order plus the issuing fee.I'm gonna give you some brief information on how to fill out a money order. This is where you should write what the money is for. It helps to include other necessary information, like an account number or order number. Fill in the recipient and your address; for bills, include an account number; sign it; keep proof of payment. How to fill out a Money Order. It's easy to fill out a money order - watch the video to learn more. 1. Fill in the payee's name. Put the payee's name on the line labeled "Pay to the order of" or "Pay to.