Paying for things with a phone has worked in Japan for four years. Commuters touch a handset to a reader at the barrier, buy a drink from a machine with it, settle a bill in a shop with it, and nobody there considers this remarkable.
Everywhere else it is trials. Pilots in one city, a partnership announced with two banks and a transport operator, a press release, and then nothing, repeatedly, for years.
The gap has nothing to do with the technology, which is old and works. It has to do with how many organisations have to agree.
Japan got there because one operator was in a position to decide. NTT DoCoMo specified what went into the handsets, ran the network they connected to, held the customer relationship, and had the standing to bring the banks along. One party could make the call and everybody else adjusted around it.
Now count the parties required elsewhere. The handset manufacturer has to fit the chip. The network operator has to support it and would like a fee. The bank has to issue the credential. The card scheme has to authorise the transaction and takes its percentage. The retailer has to buy new terminals, and the retailer is the one already complaining loudest about card fees.
Five organisations, every one of them wanting a share of a transaction that currently works fine with a piece of plastic, and not one of them able to compel the others.
So every trial dies at the same point. Not at the technical stage, which succeeds, but at the commercial one, where somebody works out that their cut is smaller than what they get today.
Worth saying plainly: nobody is asking for this. A card is fast, it already works everywhere, and it survives a flat battery. The improvement offered to the person paying is that they carry one fewer object, and that is not enough to overcome any friction at all, let alone a checkout that fails in front of a queue.
It happens when one party gets enough leverage to stop asking permission. Either an operator with a large captive base, or a handset maker whose customers will change bank rather than change phone. Until somebody can dictate rather than negotiate, this stays where it has been since 2004, which is a slide in a presentation about the year after next.