How to spot a counterfeit or altered note

Before money changes hands, a few minutes of inspection saves a lot of regret. Counterfeits and altered notes circulate in the collector market, but most give themselves away to a careful eye and hand. You don't need lab gear — you need to know what genuine notes do that fakes struggle to fake.

Start with feel: paper and printing

Genuine banknote paper is not ordinary printer stock. It has a distinct snap and texture, and it survives handling that would soften regular paper. The most telling sign is the printing itself:

• Raised intaglio. Run a fingernail across the main design — on genuine notes, key elements are printed with raised ink you can feel. Counterfeits printed flat by inkjet or laser feel smooth all over.
• Crisp, unbroken lines. Under magnification, genuine engraving shows sharp, continuous lines. Fakes often reveal dot patterns, fuzzy edges, or broken lines where a printer struggled to reproduce fine detail.

If a note feels papery-soft and prints completely flat, treat it with serious suspicion.

Hold it to the light

Many security features only appear in transmitted light:

• Watermark. A genuine watermark is created in the paper itself and shows soft, three-dimensional shading when backlit. A printed-on imitation looks flat, too dark, or sits on the surface.
• Security thread. Look for an embedded thread running through the paper, visible as a continuous line against the light. Fakes may print a fake "thread" on the surface or omit it.
• Register features. Designs meant to align front-to-back will line up perfectly on a genuine note and look slightly off on a crude copy.

Watch for altered genuine notes

Not every problem note is a printed fake — some start genuine and get "improved":

• Added or strengthened features — touched-up serials, repainted seals, or enhanced detail to fake a rarer variety.
• Trimming — edges cut down to fake better centering or remove damage; check for margins that are too tight or uneven.
• Repairs and restoration — tape, fill, washing, or pressing meant to hide folds and tears. Raking light across the surface reveals worked-on areas.
• Cleaned or pressed paper — unnaturally bright or flat-looking paper that's lost its original texture.

Alterations don't just risk authenticity — they destroy value with serious buyers even when the note is otherwise genuine.

The fast field check

When you can't run every test, do these three: feel the paper for raised intaglio, tilt under raking light for repairs and trimming, and backlight for the watermark and thread. Anything that prints completely flat, lacks a paper watermark, or shows a surface-only "thread" is a red flag worth walking away from.

When in doubt, get it certified

For any note where real money is on the line, the safest move is third-party authentication and grading. A note sealed in a holder with an expert opinion removes the guesswork — which is exactly why the market pays more for certified examples. NoteLens helps you identify the likely variety and read a reference range, but it is not an authenticity test; treat a scan as the start of due diligence, not the end.

> Value figures are market reference range estimates — not appraisals, authentication, or investment advice.