Bank of England Wiki
Provided both banks/building socities are direct participants in Faster Payments, payments are usually available almost immediately, although they can sometimes take up to two hours. These timescales can still apply if either the sending or receiving bank is not a direct participant of Faster Payments, however some payments will take longer, especially outside normal working hours. You should talk to your bank/building society if the speed of the payment is particularly important. As a minimum, all electronic payments must be made available by the end of the next business day.
Can Faster Payments be reversed?
Once sent, a Faster Payment cannot be reversed - this means the recipient can be sure the funds are theirs as soon as they appear in their account. It’s vital to double check the sort code and account number before sending a payment: payments are processed only using these numbers and getting them wrong is like sending a letter with the wrong address and post code. If you make a mistake (such as paying the wrong beneficiary, or sending the wrong amount) unfortunately there is no guarantee that money can be recovered, however there are processes in place for your bank or building society to follow to try to get your money back. More information on payments in error can be found here.
How can I send a payment using Faster Payments?
You don’t have to do anything out of the ordinary to take advantage of the world-leading service offered by Faster Payments. Most internet, mobile or telephone banking payments are now processed using Faster Payments, although the separate Bacs or CHAPS payment systems might be used for certain payments - for example for very large amounts, or to set up a batch of payments in advance. You should contact your bank or buidling society directly for more information on the exact process they follow to decide whether to use Faster Payments or not.