On what date did the United Kingdom begin decimal currency?

The United Kingdom began decimal currency on 15 February 1971, known as Decimal Day.

Before the change, one pound was divided into 20 shillings and each shilling into 12 pence, making a pound worth 240 old pence. The new system divided a pound into 100 new pence, greatly simplifying calculations for shops, banks, and the public.

The government had announced the plan in 1966, and preparations included public information campaigns, staff training, and the introduction of decimal coins. For a period, old and new coins circulated together, although some old coins were withdrawn quickly. The halfpenny was eventually introduced in 1971 and later abolished in 1984.

The United Kingdom was not the first country to decimalize its currency, and the Republic of Ireland changed on the same date. The United Kingdom retained the pound as its currency; Decimal Day changed the subdivisions, not the currency’s name.