Going slightly outside the direct thrust of your question (why more than one account) and viewing the larger picture, it is actually only how the banks choose to operate that makes not only having two accounts sensible but moreover constantly opening new ones. Banks, like insurance companies, rely on their customers not watching things meticulously and the terms of accounts (interest, charges, uses, etc.) tend to deteriorate over time just like insurance renewal premiums increase inordinately from year to year. On the other hand, banks offer new accounts with the best conditions (which then drop) and insurance companies offer new customers cheap policies. This has been going on for perhaps 40 years or more and the banks and insurance companies think it is clever because it actually works and makes them money (due to the inertia in the population). My bank manager of quite a few years ago (he and I became personal friends) told me quite openly that if it were up to him (it wasn't, he was of course just an employee) he would quite literally have only one account: A current, savings and lending account rolled into one. When you are in credit you get interest paid and if in debit you get charged interest, all according to a published table. If you want to borrow you agree that with the bank and pay the same relevant interest, including providing a security when taking out a loan for a house or anything else involving a large amount. I have often wondered what would happen if a bank decided to take up such a policy/operation - would it be popular or not ? I certainly know I would take my business there unless there was a compelling reason not to such as really poor interest rates differentials - they would however probably take aim of the general market anyway. One thing seems likely, they would be more transparent and perhaps also more stable than the familiar ones.