I work in a Post Office and sell quite a lot of Postal Orders. There are still people who don't have bank accounts (yes, really!) who use them to send money to people/organisations. You can buy them crossed (so they can only be paid into a bank account), or uncrossed so they can be cashed at any Post Office (it's a good way to send children money for their birthday - they enjoy cashing them in!). There are fees, eg a postal order for £10 will cost you £11, and you can only pay for them in cash, unlike most Post Office services which you can pay for by card or cheque.