If the Money Order has been cashed, you will receive a copy of the front and back and if not, a stop payment will be placed and the Money Order reissued to you after standard 30 to 45 day processing time. 2. MoneyGram. How long until expiration: Money orders are valid for one year after purchase. After a year, you can still cash the money order, but you’ll have to pay a service fee. When you cash the money order, the service will be deducted from the face value of the money order.