Despite almost two years of being told about the changes, and a £16m publicity campaign, only a third of telephone callers were last week using the new ``01'' dialling codes.
BT has prepared itself for up to three or four million misdialled calls per hour at peak times, which from today will fail to get through to anything more than a taped message.
BT says the biggest problem will be the automatic dialling programmes of faxes and computers that have not been altered. They will continue to re-dial wrong numbers, creating an increasing strain on the system.
Alan Croft, BT's Phoneday project manager, said last week: ``Latest market research shows that 96 per cent of businesses and 94 per cent of residential customers know about the change, but a quarter of businesses admit that they have yet to act.''
BT had to alter dialling codes in order to cope with the extra capacity created by demand for new telephone services, such as faxes, computer modems and mobile phones.
Most codes have a ``one'' added to the first zero, so that Cardiff, for instance, changes from 0222 to 01222 and inner London from 071 to 0171. Five cities - Leeds, Sheffield, Nottingham, Leicester and Bristol - have been given totally new codes and an extra digit to preceed each six-figure number.
Bristol, for instance, changes from 0272 to 0117, with a ``9'' preceeding each of the old numbers. Nottingham changes from 0602 to 0115, also with a "9". Leeds changes from 0532 to 0113 and an extra ``2'' ; Leicester to 0116, with a "2" ; and Sheffield to 0114, with a "2".
Anyone making an international call from today will have fewer digits to dial, with thechange from ``010'' to the new ``00'' code. Freephone codes, such as 0800, and the 0860 mobile phone code and 0891 information code remain.
BT's free helpline will continue to operate ,on 0800 010101.Reuse content