For centuries, Britain relied on a coinage system of pounds, shillings and pence. With twelve pennies in a shilling and 20 shillings in a pound, it was a complex structure for everyday use. On 15 February 1971 this all changed on Decimal Day with 100 pennies in a pound and the introduction of new coins.
Decimal Day
The challenges of the pre-decimal system had been recognised as early as 1847, when Sir John Bowring MP called for it to be replaced with a currency based on units of ten.
In 1961, the Government set up a committee to consider decimalisation. It recommended change, and on 1 March 1966, Chancellor James Callaghan announced that pounds, shillings and pence would be replaced by a system based on 100 units to the pound.
While names like cents and dollars were considered, pounds and pence were retained, alongside five new coins inspired by the existing designs.
Decimal Day was set for 15 February 1971, when the new coins entered circulation marking a major turning point for the nation’s currency and The Royal Mint.
Decimal Day at The Royal Mint
Switching to decimal currency was a huge undertaking. People and businesses across Britain needed clear guidance to make the transition as smooth as possible, while entirely new coins had to be designed, produced and rolled out.
The scale of the task was enormous, so much so that The Royal Mint outgrew its home at Tower Hill. A new, purpose-built facility was established in Llantrisant, South Wales, officially opened by Her Majesty The Queen in 1968. From there, production began on the first of nearly six billion coins needed to bring decimalisation to life.
Production
The new production lines at Llantrisant made minting faster and more efficient than ever before. By 1969, over 50 million coins were being produced each week, compared to just half that number in a whole year a century earlier.
While Tower Hill and selected contractors continued supplying blanks, The Royal Mint quickly built up a vast stockpile of decimal coins. In total, more than two billion were struck ahead of 15 February 1971, ensuring there was no risk of shortage.
After Decimal Day, production at Tower Hill declined, and by 1972 Llantrisant had become fully self-sufficient, bringing coin production in London to an end.
In November 1975, a 1974-dated gold Sovereign was the final coin struck at Tower Hill, marking the end of an era with a special ceremony. By then, most staff had already relocated to Llantrisant, taking The Royal Mint’s historic coin collection with them. As the doors closed in London, a new chapter in The Royal Mint’s story was just beginning.
New Coins
By Decimal Day, the country was ready. The changeover passed far more smoothly than anyone had dared to hope, and the new coins quickly took their place in numismatic history. Since then, the coinage continued to evolve. The sixpence was withdrawn in 1980, followed by the halfpenny in 1984. New denominations were introduced, including the 20p in 1982 and the £1 coin in 1983, while the 5p and 10p were reduced in size in the early 1990s. A smaller 50p followed in 1997. By 1992, every circulating coin featured the reigning monarch, something not seen since medieval times.
The first of the new coins, the 5p and 10p, entered circulation in April 1968. Featuring fresh heraldic designs, they matched the size and value of the existing shillings and florins, allowing them to circulate side by side as seamless ‘decimal twins’.
To help the nation adjust, old and new currencies circulated together, supported by widespread publicity and information campaigns designed to keep confusion to a minimum.
