Coins of the pound sterling chronologically. All genuine UK coins are produced by the Royal Mint. The same coinage is used across the United Kingdom: unlike banknotes, local issues of coins are not produced for different parts of the UK. The pound coin until 2016 was produced in regional designs, but these circulate equally in all parts of the UK (see UK designs, below). Every year, newly minted coins are checked for size, weight, and composition at a Trial of the Pyx. Essentially the same procedure has been used since the 13th century. Assaying is now done by the Worshipful Company of Goldsmiths on behalf
Coins of the Republic of Ireland were widely accepted in Ireland, and conversely to a lesser extent. In 1979 Ireland joined the Exchange Rate Mechanism and the Irish pound left parity with sterling; coin designs introduced after this differed between the two countries. The first coins minted in Ireland were produced in about 995 AD in Dublin for King Sitric, the Hiberno-Norse King of Dublin. These penny coins bore the head and name of the king and the word "Dyflin" for Dublin. John of England was among the first Anglo-Norman monarchs to mint coins in Ireland; these were farthings, halfpennies and pennies. It was not until