How to spot a fake banknote
Reviewed on 1 September 2026 · By the Detectalia technical team
In the UK, the £20 is the most counterfeited note, and any business near tourism or currency exchange handles euros too — where the €20 and €50 account for around 80 % of forgeries. The good news: every genuine note carries security features you can check in seconds by feeling, looking and tilting.
Feel: the material and the raised print
Bank of England notes (£5 to £50) are printed on polymer — a thin, flexible plastic that feels smooth and slightly waxy, springs back when crumpled and does not tear at the edge like paper. Run your finger over the words «Bank of England» and the large value numeral: on a genuine note the ink is raised and you can feel it.
Euro notes are the opposite: 100 % cotton paper, crisp and firm, never limp or waxy like ordinary paper. On the front you will feel raised lines along the edges, on the main motif, the large lettering and the value numeral. Most counterfeits are printed on ordinary paper or flat plastic and lose this feel immediately.
Look: the see-through window and the watermark
Every Bank of England polymer note has a large see-through window with the monarch's portrait in it, plus a smaller secondary window on most denominations. The portrait must be clearly visible from both sides — crude fakes print over the window or fake it with a glued patch.
For euro notes, hold the note against the light and check three things: the watermark with the portrait of Europa and the value numeral, the security thread — a dark line running through the note with the word «EURO» and the value — and, on Europa-series notes, the portrait window at the top of the hologram, which becomes transparent.
Tilt: holograms and colour-shifting ink
Tilt a polymer note and the hologram beneath the see-through window changes between the value and the word «Pounds». On the £20 and £50, the metallic image over the window changes colour, and the foil patches shift between images as the note moves. Look also for the ultra-fine metallic details around the window — the hardest part for a counterfeiter to copy.
On a euro note, the holographic stripe or patch alternates between the value, the € symbol and the portrait of Europa. The shiny numeral in the bottom-left corner of the front — the «emerald number» — shifts from emerald green to deep blue with a band of light that rolls up and down. No photocopier reproduces both effects at once.
When the eye is not enough
The feel-look-tilt method works, but it demands attention, light and time — exactly what is missing at a busy till with a queue. Mid-quality counterfeits survive a quick glance, and no cashier can check three security features on every note they take, in two different currencies.
That is why businesses with real cash volume delegate the check to an automatic fake note detector: it analyses infrared, ultraviolet and magnetic ink, the metallic thread, size and thickness in half a second, and decides on its own, with no interpretation from the cashier. Devices that pass the European Central Bank's official tests against real counterfeits appear on its public list of tested devices — and Detectalia detectors verify pounds as well as euros.
Frequently asked questions
Which notes are counterfeited most?
In the UK, the £20 by a wide margin — it is the denomination that moves most through tills. In the euro area, the €20 and €50 together account for around 80 % of counterfeits withdrawn, according to European Central Bank data.
Can a phone app check whether a note is genuine?
Apps can help you learn the security features, but they cannot analyse magnetic or infrared inks: they are no substitute for a full manual check or a tested counterfeit money detector.
Can a worn or damaged note look fake?
Yes. On a heavily worn genuine note some features are hard to make out. If in doubt, a suspect note can be submitted for analysis — via your bank or the Bank of England's process — and if it turns out to be genuine you are reimbursed in full.