Offer your thoughts or opinion on the input financial query or topic using your financial background.

Why do UK banks require monthly “pay in” into current account?
Banks are not your friends, they are not performing services for you because they like you. They are a business, and they make money by borrowing money from you at low interest and loaning it out at higher interest. They are trying to persuade you to deposit more money (however briefly) in their bank so they can loan out more money. They are probably also counting on the fact that most folks won't go to the trouble of setting up accounts at multiple banks with the interlocking automatic transfers, in order to meet the required deposit threshold. That lets them save on the interest payments to consumers that are individually tiny, but significant in the aggregate.