What to do with expired bank notes as old £20 and £50 go out of circulation

The new-look polymer banknotes we all see in daily life are commonplace now, even though some of the currency hasn’t been around for as long as some people might assume.

The first of the notes to be introduced was the Winston Churchill £5, which first entered circulation in 2016 and featured a holographic image change, see-through window, green foil patch, and many other…