My friends know my mobile number. When they want to send me money, then I have to give them my sort code and account number. Having a mapping from mobile number to account credentials seems sensible to me.

I'm set up on PayM, but no one else seems to use it.

I love it, but find it takes around the same amount of effort to send money by PayM as it does to send it by regular bank transfer to somebody already set up in my mobile banking app (my main use case is usually sending smallish amounts of cash to my kids, like a modern-day Al Bundy). PayM could do with a really nice streamlined app of its own, rather than being buried deep within each of my banks' own apps.

I've only used it once (I no longer live in Britain) but I liked the confirmation. I put in a friend's number, and the bank showed me his name.

Here in Hong Kong we can make direct account transfers at the ATM, though you still need to know the recipient account number, after you enter the number it will show the recipient account name (with some chars masked) which is always a nice confirmation that you've entered the right digits.