Off-centre strike Coin Errors
What is a off-centre strike error?
An off-centre strike happens when the planchet (blank) doesn't fully seat in the collar before the dies hit. The result is a coin where the design is shifted to one side and a corresponding crescent of blank metal sits on the opposite edge. Severity is graded as a percentage off-centre — a 5% off-centre is a minor curiosity, while a 30%+ off-centre with a fully visible date is highly collectable.
How to spot one
- Hold the coin under good light and look for asymmetry — design pushed to one side.
- Identify the "offset crescent" — a rim of blank metal where the design should have continued.
- For decimal coins, severe off-centres often cut off part of the date — coins still showing the full date are worth more.
- Estimate the percentage off-centre — measure visible blank metal vs total coin width.
Authentication
Off-centre genuine errors retain Royal Mint metal, weight and design quality. Counterfeit "off-centres" are usually post-mint mechanical damage — look for tooling marks, deformed edges, or impossible angles.
Famous UK examples
Common error on 50p coins. >20% off-centre with visible date can clear £100.
Very rare on the 12-sided £1 (2017+) due to the bimetal collar — pre-2017 round £1 off-centres are more common.
Common; only severe (>30%) examples carry premium.
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: