Uk mobile phone numbers talk dirty
The 0845 range can have NSN length as 10 or 7 digits. There are no telephone numbers in the UK with an NSN length of 8 digits. It has a four-digit area code (after the initial zero) and a six digit subscriber number, and is known as 4 6 format.
These area codes were changed by adding a "1" directly after the initial zero as a part of Ph ONEday in 1995.
These six areas have a three-digit area code matching the pattern 1x1 (after the initial zero) and a seven digit subscriber number, and this is known as 3 7 format.
This is the geographic number format for the second round of large cities and towns moved to brand-new three-digit area codes.
The overall structure of the UK's National Numbering Plan is: In the United Kingdom, area codes are two, three, four, or, rarely, five digits long (after the initial zero).
Regions with shorter area codes, typically large cities, permit the allocation of more telephone numbers as the local number portion has more digits.
The "area code" is also referred to as an "STD (code)" (subscriber trunk dialling) or a "dialling code" in the UK.
If a number begins with 09 then they are usually ‘premium rate’ service numbers; whilst those beginning with 118 are directory enquiry numbers.
This leads to a restriction as to which initial digits can be used for subscriber numbers within those four-digit area codes, e.g.
in the 01387 four-digit area code, subscriber numbers cannot begin with a 3 because 013873 is a separate five-digit area code; likewise in the 01946 four-digit area code, subscriber numbers cannot begin with a 7 because 019467 is a separate five-digit area code.
That is, almost all (01xxx) area codes now have only six digit local numbers, e.g.
(a small selection) Six of the four-digit area codes are known as "mixed" areas as they share those four digits with the twelve five-digit area codes.
These towns always have a mixture of six and five digit local numbers, each type allocated in specific DE blocks; e.g.