The Bank of England has provided some advice on identifying fraudulent copies of new banknotes bearing the likeness of King Charles III which have started to enter circulation.

The new notes will gradually replace the Queen Elizabeth II notes currently in circulation which are withdrawn due to damage and will be gradually issued as demand increases. As with the introduction of any new notes, there is a window of opportunity for fraudsters who may take advantage of their unfamiliarity in retail and other outlets.

Among the features that can be used to determine authenticity – which are the same as for the earlier notes – are the coloured foil patch on the back of the notes, which varies in colour depending on the denomination, and the monarch’s portrait in a transparent window.

The Bank of England’s updated advice also highlights a silver foil patch containing a hologram below the main see-through window, a 3D image of the coronation crown appears above it, a second, smaller window in the bottom corner of the £20 and £50 notes, a metallic patch on the rear, raised print and ultraviolet numbers.

The reverse side of the current English polymer banknotes are unchanged, featuring Sir Winston Churchill on the £5, Jane Austen on the £10, JMW Turner on the £20 and Alan Turing on the £50, and are also used in Wales. Notes issued in Scotland and Northern Ireland do not show the monarch and have other images.

Shoppers can still use current circulating £5, £10, £20 and £50 notes carrying the portrait of the late Queen.