Clipped planchet Coin Errors
What is a clipped planchet error?
A clipped planchet error occurs when the punching machine that cuts blanks from the metal strip overlaps a previous punch hole. The new blank has a curved bite missing from one edge. The remaining design is normal but the rim and design are cut off where the clip is. Genuine clipped planchets show a smooth, curved missing arc — not a jagged break.
How to spot one
- Smooth curved arc missing from the edge — not a jagged break or bite.
- The arc curvature should match the diameter of the coin (i.e. the missing piece would have been another planchet).
- Where the clip meets the coin edge, look for the "Blakesley effect" — a flat or weakly-struck region directly opposite the clip.
- Weight is reduced proportional to the missing area.
Authentication
Counterfeit clips are typically jagged, post-mint cuts. Genuine planchet clips are perfectly smooth arcs and show the Blakesley effect on the opposite rim.
Famous UK examples
Common error type, usually small clips trade £10-£25.
Smaller denominations, smaller premiums.
Key-date UK coins worth examining
Errors on key-date coins compound rarity — the host coin is already scarce, and the error multiplies the value. Browse the rarest UK coins in our catalogue: