Retailers are being urged to ensure they are prepared for the new £20 note before its introduction on February 20.

The new £20 note is printed on polymer and features the artist JMW Turner on the reverse but retains the distinctive £20 purple colour.

According to the Bank of England it is the most secure banknote yet with sophisticated security features making it difficult to counterfeit but simple and quick to check.

The note has a see-through window in which Margate Lighthouse appears in gold foil with the Turner Contemporary gallery in blue, and the foils are silver on the back. There is also a hologram image on a metallic patch under the main window which contains the word “Twenty”. This changes to “Pounds” when the note is tilted from side to side.

The new £20 note will be the first to feature the signature of Sarah John, the Bank’s chief cashier. She said: “The new £20 is an important part of our commitment to providing banknotes that people can use with confidence. Our polymer notes are much harder to counterfeit and, with the £20 being our most common note, this marks a big step forward in our fight against counterfeiting.”

Paper £20 notes, featuring Adam Smith, will remain legal tender and will be gradually withdrawn as they are banked. Notice will be given six months ahead of legal tender status being withdrawn.