I celebrated the 54th anniversary of UK Decimal Coinage today by spending a 1971 1p and a 1971 2p in my local supermarket.
February 15, 1971 was the official changeover day. It was decided that a Monday in mid-February was a good day for the banks as they wouldn't be too busy.
The bronze half new penny, one new penny and two new pence coins were released into circulation and became legal tender that day.



The two old £sd coins that became immediately obsolete on 15th February were the nickel-brass threepence, a relatively new coin only introduced in 1937, and the large bronze penny, introduced in 1860 to replace the even bigger copper penny. These coins remained legal tender but most larger stores and public transit operators would only accept them if coins up to a value of 6d (two-and-a-half new pence) were tendered together. The 1d and 3d were demonetised on August 31, 1971.
The pre-decimal sixpence was worth two-and-a-half new pence. It had been planned to withdraw it in 1971, but a campaign from the public and from the vending machine industry gained it a reprieve. However, by the end of the year sixpences had virtually disappeared from circulation, partly because inflation meant that vending machines were rapidly changed to take larger coins. Strangely enough the old sixpence remained legal tender until 1980. The old halfpenny and halfcrown had both been demonetised in 1969, well ahead of decimalization. The shilling and florin continued to circulate alongside the decimal 5p and 10p, which were the same size, and the seven-sided 50p had replaced the 10-shilling note in October 1969.
One place where the introduction of decimal currency had no effect was the Post Office. February 15th was right in the middle of a long strike by postal workers. Stamp collectors who managed to get first day covers of the new decimal stamps had to wait a long time for them to be delivered!
I can remember my last ever transaction using old pennies. On July 9, 1971 I was in a car with my parents and we came to a toll tunnel. The toll was twelve-and-a-half new pence (an easy 2/6d in the old money). My Dad had a 10p coin but no other change. I had a threepenny bit and three old pennies in my pocket, and gave them to him for the toll. I can't remember if he ever repaid me!
