Decimal Day use pennies or threepenny pieces, to pay them in multiples of 6d (p, the lowest common multiple of the two systems). Bus companies (at that time many state-owned by the National Bus Company) were another exception, going decimal on Sunday 21 February. Decimal Day itself went smoothly. Criticisms included the small size of the new halfpenny coin and the fact that some traders had taken advantage of the transition to raise prices. Some used new pennies as sixpences in vending machines. After 15 February, shops continued to accept payment in old coins, but always issued change in new coins. The
Decimal Day Day to enable them to give change immediately after the changeover. Banks were closed from 3:30 pm on Wednesday 10 February 1971 to 10:00 am on Monday 15 February, to enable all outstanding cheques and credits in the clearing system to be processed and customers' account balances to be converted from £sd to decimal. In many banks the conversion was done manually, as most bank branches were not yet computerised. February had been chosen for Decimal Day because it was the quietest time of the year for the banks, shops, and transport organisations. Many items were priced in both currencies