Before the 1970s, earlier efforts in the United Kingdom to introduce decimalised currency had failed; in 1824, the United Kingdom Parliament rejected Sir John Wrottesley's proposals to decimalise sterling, which were prompted by the introduction of the French franc three decades earlier.

Following this, little progress towards decimalisation was made in the United Kingdom for over a century, with the exception of the two shilling silver florin, first issued on 1849, worth ⁠1/10⁠ of a pound.

A double florin or four shilling piece, introduced in 1887, was a further step towards decimalisation, but failed to gain acceptance and was struck only between 1887 and 1890.

Though little further progress was made, The Decimal Association, founded in 1841 to promote decimalisation and metrication, saw interest in both causes boosted by a growing national realisation of the importance of ease in international trade, following the 1851 Great Exhibition; it was as a result of the growing interest in decimalisation that the florin was issued.

[3] A final report in 1859 from the two remaining commissioners, Lord Overstone and Governor of the Bank of England John Hubbard, came out against the idea, claiming that it had "few merits".

In 1960, a report prepared jointly by the British Association for the Advancement of Science and the Association of British Chambers of Commerce, followed by the success of decimalisation in South Africa, prompted the Government to set up the Committee of the Inquiry on Decimal Currency (Halsbury Committee) in 1961, which reported in 1963.

The former Greater London Council leader Bill Fiske was named as the Chairman of the Decimal Currency Board.

It would have resulted in the "decimal penny" being worth only slightly more than the old penny, an approach adopted in South Africa, Australia and New Zealand in the 1960s, adopting respectively the South African rand, Australian dollar and New Zealand dollar equal in value to 10 shillings.

Under the new system, the pound was retained, but was divided into 100 new pence, denoted by the symbol p. New coinage was issued alongside the old coins.

A substantial publicity campaign took place in the weeks before Decimal Day, including a song by Max Bygraves called "Decimalisation".

[10] The BBC broadcast a series of five-minute programmes, titled "Decimal Five", to which The Scaffold contributed some specially written tunes.

[11] ITV repeatedly broadcast a short drama called Granny Gets The Point starring Doris Hare, in which an elderly woman who does not understand the new system is taught to use it by her grandson.

[12] At 10 a.m. on 15 February and again the following week, BBC 1 broadcast 'New Money Day', a Merry-Go Round schools' programme in which puppet maker Peter Firmin and his small friend Muskit encountered different prices and new coins when they visited the shops.

[13][14] Banks received stocks of the new coins in advance, which were issued to retailers shortly before Decimal Day to enable them to give change immediately after the changeover.

February had been chosen for Decimal Day because it was the quietest time of the year for the banks, shops and transport organisations.

[17] Because of extensive preparations and the publicity campaigns organised by the British government, Decimal Day itself went smoothly.

Within two weeks of Decimal Day, the old penny (1d) and old threepence (3d) coins had left circulation, and old sixpences had become somewhat rare.

[citation needed] However, some slang terms, such as "quid" and "bob", previously used for pounds and shillings respectively, survived from predecimal times.

Amounts denominated in guineas (21s or £1.05) were reserved still for specialist transactions, and continued to be used in the sale of horses and at some auctions, amongst others.

[citation needed] The willingness of Britain's younger population to embrace decimalisation also helped, with elderly people having greater difficulty in adapting; the phrase "How much is that in old money?

became associated with those who struggled with the change, before in the following decades coming to refer to conversions between metric and imperial weights and measures.

Commemorative 'decimal' Crowns dated 1972, 1977, 1980 and 1981 remain legal tender (with a face value of 25p) as do the £5 coins issued from 1990 onwards.

[28] This arrangement continued until 1979 when Irish obligations to the European Monetary System led to Ireland breaking the historic link with sterling.

Pre-decimal Irish coins may still be redeemed at their face value equivalent in euros at the Central Bank in Dublin.