Coin Error Guide
Complete reference of known minting errors, die varieties, and valuable mistakes. Learn to spot DDOs, RPMs, wrong planchets, and more — some worth thousands or even millions.
Occurs when a working die receives an additional, misaligned impression from the hub. Creates visible doubling on the obverse (front) of the coin — on dates, lettering, and design elements.
Similar to DDO but occurs on the reverse (back) of the coin. Doubling visible on reverse lettering, denomination, and design elements.
When the mint mark punch was applied more than once in slightly different positions, creating overlapping or ghosted mint marks.
On Lincoln Memorial cents (1992-2000), the AM in AMERICA on the reverse can appear close together (touching) or wide apart. Business strikes should have Close AM; proofs should have Wide AM. When swapped, they become valuable errors.
The coin blank (planchet) was not properly centered between the dies during striking, resulting in part of the design missing.
Struck without the retaining collar that normally shapes the coin's rim and edge. The coin spreads out wider than normal with a flat or missing rim.
The planchet (coin blank) was improperly cut from the metal strip, resulting in a missing section. Can be curved, straight, or irregular clips.
A coin struck on a planchet intended for a different denomination or even a different country's coin. These are among the most valuable error types.
The coin was struck twice by the dies, with the second strike offset from the first. Creates a dramatic overlapping design.
Raised lines (cracks) or lumps (breaks/cuds) on the coin's surface caused by fractures in the die. Cuds occur when a piece of the die breaks away from the edge.
A foreign object (grease, cloth, wire, staple) was between the die and planchet during striking, creating an impression or blank area.
The obverse and reverse dies are misaligned rotationally. When you flip the coin, the reverse is rotated from its normal orientation.
One or both of the outer clad layers are missing, exposing the copper core. The coin appears copper-colored on one or both sides.
