Brockage Coin Errors
What is a brockage error?
A brockage forms when a struck coin sticks to one of the dies and acts as a die for the next strike. The next blank planchet is struck on one side by the actual die and on the other by the stuck coin, producing a mirror image of the design pressed into the planchet. A full brockage shows a complete mirror image and is one of the rarest error types on modern UK coins.
How to spot one
- One side has a normal incuse (sunken) image — but as a mirror reflection of the other side.
- The "incuse" side appears pressed in rather than raised.
- Letters and numbers read backwards on the brockage side.
- Partial brockages (where the stuck coin only covered part of the planchet) are more common than full brockages.
Authentication
Genuine brockages are extremely rare on modern UK coins. PCGS or NGC certification is highly recommended for any claimed brockage. Counterfeits include intentionally pressed coins which lack die-strike sharpness.
Famous UK examples
Rare — the small denomination keeps prices under £1,000.
Major auction sales documented for clean full brockages.
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: