At least £2.1bn worth of old £10 notes need to be spent or exchanged before they cease to be legal tender, the Bank of England says.
The deadline to spend or exchange old £10 notes - featuring naturalist Charles Darwin - is 1 March.
To exchange an old tenner, people can either post the notes to the Bank of England, or visit the Bank in person in the City of London.
The Bank will exchange all old £10 notes indefinitely.
The Bank says people can also try to exchange paper tenners at their local bank or post office.
However they are not legally required to accept old notes after the deadline.
