Page "Mint-made errors" Paragraph 32

Most error coins demand a premium when sold, if they are modern coins, dependent upon the rarity of the type of error as well as the rarity of that type of error on a particular denomination.

Overdates, particularly of 20th century coins, are in demand but other errors may be very minor or of interest only to specialists.

The value of error coins has been subject to much debate and the value is usually determined between the dealer and the collector.

Conversely, errors on ancient, medieval and higher value coins are usually detrimental to the coin's numismatic value.