Fill in the recipient and your address; for bills, include an account number; sign it; keep proof of payment. Check that the money order amount is correct.When filling out a money order, you'll need some basic information, such as the recipient's name and your address. Fill out the money order at the counter with a retail associate. Pay the dollar value of the money order plus the issuing fee. To fill out the money order, you will need to "Pay to" U.S. Department of Homeland Security. Write the payee's name in the "Pay to" field. Do this first, because that way, if you lose the money order, no one else can find it and cash it. How to fill out a USPS Money Order. How to fill out your check or money order. 1.