This one ^

It's illegal in the UK apparently. Considered a 'surcharge'. I saw this shared by David nostr:nprofile1qqsd7gqv4s60d743gfv8x4z09krv6zmn6x02sswcfsrt0ymshw3pfqcpzemhxue69uhk2er9dchxummnw3ezumrpdejz7qgwwaehxw309ahx7uewd3hkctc8wns6f recently. Section 13.1

https://assets.publishing.service.gov.uk/media/5b2d09bae5274a55bb5790cb/payment-surcharges-guidance-update.pdf