We've updated our payment system to make it even more secure. We made these changes in line with new Strong Customer Authentication regulations (from 14 September 2019) for online payments in Europe. This means that when you make a credit card payment, you'll need to go through an extra authentication step.
To make authenticated payments, you need two of the following: something you know, something you own, and something you are. Something you know is a password, a passphrase, or a code. Something you own is a device, like a phone, laptop or smartwatch. Something you are means a fingerprint, face ID, voice pattern, or iris scan.
As an example, you might have the new payment system set up with a password and your phone as your two methods of authentication. In that case, you'll need to enter both your password and the code sent to your phone when making a payment.