Decimal Day old coins were returned to the banks and in this way the bulk of them were quickly taken out of circulation. The new halfpenny, penny, and twopence coins were introduced on 15 February 1971. Within two weeks of Decimal Day, the old penny (1d) and old threepenny (3d) coins had left circulation, and old sixpences were becoming rare. On 31 August 1971, the 1d and 3d were officially withdrawn from circulation, ending the transition period. The government intended that in speech the new units would be called "new pence", but the public decided that it was clearer and quicker to
Penny (Irish pre-decimal coin) Penny (Irish pre-decimal coin) The penny (1d) () coin was the third smallest denomination of the pre-decimal Irish pound, worth of a pound or of a shilling. To express an amount, penny was abbreviated to "d", e.g. 1d, from the Roman "denarius". It was introduced in 1928 to replace its British counterpart, used when all of Ireland was a constituent country of the United Kingdom. The last year of minting was 1968 and it ceased to be legal tender on 31 December 1971. The coin measured in diameter and weighed 9.45 grams. The bronze coin was made up of 95.5%