When sending money to a different account, many banks now use the Confirmation of Payee scheme, which checks whether the name of the account you are sending money to matches up to the sort code and account number you type in. If the name doesn't match, the bank will let you know so you can amend any errors before making the payment.
If your bank isn't signed up, it'll be using the old system, where the only information it'll use is the sort code and account number, meaning if these details are wrongly entered the cash could end up in a stranger's bank account.
If you end up sending money to the wrong account, here's what you need to do and what happens then:
Contact your bank straightaway to let it know about the mistake. While banks can't stop payments that have already been made, contacting it as soon as possible will help speed up the process of sorting it out. It's a good idea to keep a note of all correspondence you have with the bank and also to make a note of exactly when the error was made. If you know the mistake you made (for example, you used the wrong sort code), then make a note of that too.
Your bank will act within two working days of you telling it. And it doesn't matter if you discovered your mistake after a week or even a year... though it's good financial sense to keep an eye on your account(s) to make sure your payments have reached the right recipient.
As long as there are no disputes, your money will be returned within 20 working days. Where there's clear evidence of a genuine mistake, your bank will contact the receiving bank on your behalf requesting that the money isn't mistakenly spent by the person who accidentally received it, and you'll get your money back.
If there are issues, for instance if the person you accidentally sent it to refuses to return it, you'll be notified of the outcome of the bank's investigation within 20 working days from the point that you let it know.