Fifty Pence 2021 Anniversary of Decimalisation (Machin effigy), Coin from United Kingdom - detailed information

The British fifty pence (50p) coin - often pronounced as "fifty pee" - is a unit of currency equalling one half of a Pound Sterling. It is a seven-sided coin formed as an equilateral-curve heptagon, or Reuleaux polygon - a curve of constant width, meaning that the diameter is constant across any bisection. This shape, which was revolutionary at the time of its introduction, makes it easily distinguishable from round coins both by feel and by sight, while its constant breadth allows it to roll in vending machines.

The first UK Fifty Pence coin was issued in 1969 with the classic Britannia reverse design by Christopher Ironside, which was superseded in 2008 by the Matthew Dent design for circulation coins.The denomination is also extensively used to issue circulating commemorative coins.

Beginning in 2009, the Royal Mint started issuing 50 pence coins for collectors - such as this one - which are not meant to be released in circulation, so are classified as Non-Circulating Legal Tender (NCLT).

This coin was issued to commemorate the 50th anniversary of Decimalisation in the United Kingdom. Before 15 February 1971, known as Decimal Day, the British pound was made up of 20 shillings, each of which was made up of 12 pence, a total of 240 pence. With decimalisation, the pound kept its old value and name, and the only changes were in relation to the subunits. The shilling was abolished, and the pound was subdivided into 100 "new pence" (abbreviated "p"), each of which was worth 2.4 "old pence" (abbreviated "d").

The Royal Mint says:
"This landmark moment introduced the coins we use today, and was Britain’s biggest peacetime operation. It marks a special anniversary in The Royal Mint’s own 1,100-year history and has been commemorated on a 50p coin. To celebrate this momentous occasion, the Decimal Day 50p coin features the second effigy of Her Majesty The Queen on its obverse - this portrait was created by Arnold Machin RA for decimalisation to mark the transition and help people identify the new coinage. The reverse design was created by Royal Mint employee Dominique Evans. This coin featuring the Queen’s second effigy is only available as part of the annual set."

No coins of this type were released into circulation.