The Trial of the Pyx checks that UK coins are within the limits for metallic composition, weight and size.
The history of the Trial of the Pyx dates back to the 12th century, making it one of the longest established judicial procedures in the country. The purpose of the annual trial is to check that UK coins produced by the Royal Mint are within the statutory limits for metallic composition, weight and size. The name Pyx refers to the chests in which the coins are transported, and derives from the Pyx chamber in Westminster Abbey where historically the chests were kept, along with other important items of state and church.
The Coinage Act 1971 requires a trial at least once a year to check that UK coins issued by the Royal Mint have been minted in accordance with the Act.
The signed copy of the verdict has been deposited with the records of the Queen’s Remembrancer’s Office.