Another thing with money order is that they're not exactly the most secure method of sending payments. While safer than cash, there is still a high chance that if someone was to come across a domestic money order, he could still redeem it even if he wasn't the sender or the intended recipient. Also, a lot of banks/postal services refuse to accept damaged money orders (ie. from the rain or from wear) where the processing numbers cannot be read, even if a receipt is produced.