Coins and notes : I Wish I Knew

The short version

UK coins are made by the Royal Mint. The Bank of England issues notes in England and Wales, while authorised commercial banks issue notes in Scotland and Northern Ireland. Both use layered security features, such as clear windows and holograms, that are easy to check but hard to copy.

I always assumed notes were hard to copy because the paper was special.

Today's notes are not made of paper at all.

They are plastic, and the clever part is what is built into them.

Notes made of plastic

Bank of England notes are printed on polymer, a thin, strong plastic film. The £5 came in 2016, the £10 in 2017, the £20 in 2020 and the £50 in 2021. The old paper notes were withdrawn in 2022.

Polymer lasts longer than paper and can be recycled. It also lets in features paper cannot have, such as a clear window.

Some features on a note

Window

See-through

A clear section with a metallic image, hard to print on ordinary materials.

Foil

Shiny patch

A metallic strip or patch that changes colour when you tilt the note.

Raised print

Feel it

Ink that stands up, which you can feel with a fingertip, especially on the main portrait.

Hidden image

Under light

Small details that show up only when held to the light or under ultraviolet.

Coins

Coins are made at the Royal Mint in Llantrisant, in Wales. The current £1 coin, from 2017, has 12 sides and two metals: a gold-coloured outer ring around a silver-coloured centre. It has a hologram-like image that changes between a pound sign and a rose when you tilt it, and tiny lettering on the rim.

A coin is mostly worth its face value, not its metal. Its protection comes from how hard it is to match the shape, the alloy, and the fine detail at the same time.

1 in 30

About one in 30 of the old round £1 coins was found to be fake before it was replaced in 2017.

Making money is hard because the materials are rare.

The materials are ordinary. The security comes from combining many small features, which is what makes a copy cost more than the note is worth.

Checking a note

The Bank of England recommends checking several security features rather than relying on one detail. You can feel the raised print, look through the clear window and tilt a note to see how the foil image changes. Each denomination has its own features. These checks are designed to be quick and use no special equipment, although a counterfeit can still be difficult to spot. The Bank of England's guide shows what to look for on each current note.

When each note changed

2016 The polymer £5 enters circulation.
2017 The polymer £10 and the 12-sided £1 coin arrive.
2020 The polymer £20 follows.
2021 The polymer £50 completes the set.
2022 The old paper £20 and £50 notes stop being accepted.

Note: cash is only a small part of all the money in the UK. See where money comes from. Figures are for the UK.

Sources: Bank of England, banknote security and polymer notes; The Royal Mint, the 12-sided £1 coin.

Key takeaways

UK notes are polymer; coins come from the Royal Mint.
Security comes from layers of small features.
The window, foil and raised print can be checked by hand.
The 12-sided £1 coin replaced one that was often faked.

Now you know.

Notes are plastic.

Many small layers protect them.

A forger needs all of them.

Coins and notes