Fill in the recipient and your address; for bills, include an account number; sign it; keep proof of payment. Filling out a money order is a straightforward stepbystep process.Just follow these instructions and you'll be ready to send your money. Fill it out: In addition to the payee's name, you'll need to add your name (and maybe your address) and sign the money order. To fill out a money order you need to first fill out the who the payee is, the purchasers information and sign it. How to fill out a USPS money order? The money order has a purchaser section, which you'll fill out with your name and address. Ositform-ff-ga-0523. HOW TO SEND. Create a free money order voucher to print and mail in. Please allow up to 2 weeks for mail and processing time.