The "Houblon" £50 note is set to be withdrawn from circulation by the Bank of England on 30 April 2014.
The notes featuring Sir John Houblon on the reverse will be withdrawn from circulation on 30 April 2014 and can be used normally until then.
For several months after this, most banks and building societies will accept the notes for deposit into customer accounts.
Barclays, RBS, NatWest, Ulster Bank and the Post Office have agreed to exchange Houblon £50 notes, up to the value of £200, at their branches until 30 October 2014.
The Bank of England, meanwhile, will always exchange its old series notes.
The Houblon £50 note was first introduced in 1994. The new note, featuring Matthew Boulton and James Watt, was first issued into circulation in November 2011 and will remain in circulation after the Houblon notes are withdrawn.