The biggest differences between a money order and a cashier's check are where they can be bought, how much money they represent and the guarantee for each. In most cases, a cashier's check is considered a more credible form of payment.
Purchasers can buy money orders from post offices, banks, credit unions, and convenience stores. The maximum amount of a money order varies by location, but typically, $1,000 is the maximum amount. Money orders do not carry bank guarantees, whether the purchaser buys them from a bank or not. Cashier's checks are similar, but purchasers can only buy them from a bank, and they carry a bank guarantee. The maximum amount of a cashier's check is typically $5,000.