wildcardjack: I don't know how bill acceptors work in England or other regions. American bills are slow to change because we have a lot of bill acceptors that need to remain compatible or updated, and most of them are primitive devices that you can't update to something new.

We didn't have many veding machines that took notes, and the ones that do are designed on the assumption that a new note will be issued every five years so they can be updated (as pound notes get updated every five years). Now plenty of machines take cards as well as cash.

We use coins a lot more than the USA does, with higher vales as well (up to £2) so the idea that any vending machine needs to take notes is a modern thing (unless they are change machines to feed gambling machines in arcades)