British Fifty Pence coin
The British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 decimal fifty pence
A penny is a coin or a type of currency used in several English-speaking countries. It is often the smallest denomination within a currency system.-Etymology:...

A coin is a piece of hard material that is standardized in weight, is produced in large quantities in order to facilitate trade, and primarily can be used as a legal tender token for commerce in the designated country, region, or territory....

 – often pronounced "fifty pee" – was issued on 14 October 1969 in the run-up to decimalisation
Decimal Day
Decimal Day was the day the United Kingdom and Ireland decimalised their currencies.-Old system:Under the old currency of pounds, shillings and pence, the pound was made up of 240 pence , with 12 pence in a shilling and 20 shillings in a...

 to replace the ten shilling note. Despite the coin's novel shape, there was initial confusion amongst some members of the public, with the coin being mistaken for both the old half crown
Half crown (British coin)
The half crown was a denomination of British money worth half of a crown, equivalent to two and a half shillings , or one-eighth of a pound. The half crown was first issued in 1549, in the reign of Edward VI...

 and the new ten pence piece.

In some regional dialects, particularly South Yorkshire, the coin has maintained its informal nickname of the 'ten bob piece (or bit)'.