From Faster payments website, this is why You should put through a £1 test payment
The Faster Payment System is available day and night, 365 days per year, supporting the demands of personal and business customers since its creation in 2008. The service facilitates real-time payments of up to £1m* – initiated primarily online, mobile, or via telephone banking – for millions of...
www.fasterpayments.org.uk
Faster Payments are processed in matter of seconds and once your payment is sent, it cannot be stopped or reversed.
For this reason it’s vital that you are certain that you are sending a Faster Payment to the right account. Before you make a payment to someone for the first time, double-check with them that you have the correct account number and sort code.
If you do make a mistake (such as paying the wrong beneficiary, or sending the wrong amount), there is no guarantee that money can be recovered.