Dialling code needed in parts of Dorset in UK first
People in Dorset have become the first in the UK to have to use the area code when making local landline phone calls, in a bid to free up more numbers.
The Bournemouth, Poole and Christchurch areas had been predicted to run out of numbers by 2016.
The new system will make it possible to bring in numbers where the first digit after the 01202 area code is 0 or 1.
Aberdeen, Bradford, Brighton, Middlesbrough and Stoke-on-Trent are set to follow suit in the coming years.
Those locations are also forecast to run out of available numbers by the end of 2016, telecoms regulator Ofcom said.
It had always been that when making a local call from a landline in the UK it was not necessary to dial the area code.
This meant Ofcom could not allocate any phone numbers in which the first digit after the area code is 0 or 1 because, if dialled without the area code, the number could be confused with other dialling codes.
The new system will make it possible, in parts of the country where spare numbers are scarce, to bring in numbers where the first digit after the area code is 0 or 1.
The change in Dorset will be completed by late afternoon, with people hearing a message if they forget the code.
Ofcom said the change would allow it to make almost 200,000 more 01202 numbers available.
A spokesman said: "We looked at different options, including changing numbers or adding an extra digit, but we found people preferred to use the dialling code.
"This move also releases 25% more numbers in an area code."