Both the old £50 and the old £20 notes will be withdrawn on the same day - but don't worry, there's still plenty of time to use or exchange old for new.
The new £20 and £50 notes - alongside the Churchill £5 and the Austen £10 - are part of a first series of banknotes made from polymer to replace paper ones.
Here's a look at when the new £20 note was first issued, which historical character features and when it will be withdrawn from circulation by the Bank of England.
When was the new £20 note released?
Bank of England first issued its polymer £20 note on 20 February 2020.
The polymer bank note features several security measures to prevent counterfeit currency being produced. including a hologram image change and see-through windows.
The hologram image change can be seen when the note is tilted from side to side - the wording changes between 'Twenty' and 'Pounds'.
While there should be notable differences on either side of the metallic image over the main window - the foil should be blue and gold on the front and silver on the back.
A second window, considerably smaller, is also placed in the bottom corner of the note.
These two security features should help confirm if the note is genuine £20 currency - and the Bank of England say it is the most secure banknote it has issued.
Whose face is on the new £20 note?
The new polymer £20 note features the face of artist JMW Turner.
The picture is Turner’s self-portrait, painted around 1799 and is currently on display at Tate Britain, against the backdrop of one of his most famous paintings - The Fighting Temeraire.
The Fighting Temeraire painting is a tribute to the ship HMS Temeraire, which played a distinguished role in Horatio Nelson’s victory at the Battle of Trafalgar in 1805.
The note also features Turner's signature from his will, in which he left many of his paintings to the nation, and the quote 'light is therefore colour' taken from a lecture he gave in 1818.
When do old £20 notes go out of circulation?
The last day the old £20 note can be used is on 30 September 2022 - more than two years after the new polymer £20 note was first issued by the Bank of England.
Old £50 notes will be withdrawn from circulation on the same day.
Upon release of the new £20 note, the Bank of England said it would provide six months' notice of withdrawal of the old £20 note to allow enough time for people to use or exchange.
The old £20 notes can be used all the way up to the end of September 2022 or can be exchanged for a new one via your bank, Post Office or with the Bank of England.