The £20 notes with Sir Edward Elgar on the reverse are being phased out, and from 30 June will no longer be legal tender. There will however be a grace period during which any still in charities' or anyone's possession may be exchanged at the full value.
Introduced in 1999, the design began to be phased out by the Bank of England three years ago when it introduced a new design featuring Scottish economist Adam Smith on the reverse.
The Bank of England explained that, after 30 June, "most banks, building societies and Post Offices will accept the Elgar £20 notes for deposit to customer accounts and for other customer transactions". Failing that, the Bank of England will always exchange its old notes, years into the future.
The Bank of England offers a "Know Your Banknotes" leaflet in PDF, which provides a guide to the key recognition and security features on banknotes.