Numbers in these five areas are commonly misquoted, e.g. The numbers consist of a two-digit area code matching the pattern 02x, and an eight-digit subscriber number, and this is known as 2 8 format.
The first four digits of the local number identifies a small area within the town or city.
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.
The first three digits of the local number identifies a small area within the town or city.The "area code" is also referred to as an "STD (code)" (subscriber trunk dialling) or a "dialling code" in the UK.The code allocated to the largest population is (020) for London.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.