I've been watching this with interest and I'm intrigued about folk like me who don't live in Britain, but are popping across for a visit. I presume I can still pay with a debit card, but using a smartphone to pay for stuff will not work, even if I knew exactly how it works.
Most of the UK is now cashless with either cards (credit/debit) or phone payments.

) I did a talk to Barclays Bank senior managers about the future of a cashless society in 25 years' time whereby all our transactions were via one card. It was part of a public speaking challenge.