Originally Posted by
stifle
The Bank of England on Threadneedle Street, London EC2, on the other hand, will be pleased to do so. Mrs. stifle exchanged an old £20 note there a couple of months ago.
The BoE will only exchange old bank notes. Coins are produced by the Royal Mint and cannot be exchanged once the notification period expires after a coin is withdrawn from circulation
Edited to add: I see YVR Cockroach beat me to it :-)