A hunt is on for a batch of 20 pence coins accidentally issued by the Royal Mint without a date.
Some 100,000 of these coins were issued last year - the first time such a mistake has been made for more than 300 years.
One of the coins has sold on eBay for almost 6000 pounds.
London Mint, a company that deals in collectable coins, is offering 50 pounds for each of the undated 20 pence coins because they're so rare.
