Since 28 April 2001, almost all geographic numbers and most non-geographic numbers have 9 or 10 national (significant) numbers after the "0" trunk code.
All mobile telephone numbers have 10 national (significant) numbers after the "0" trunk code.
Local customer numbers are four to eight figures long.
At the time of the change, an extra digit was added to the subscriber number.
The number of places with five digit subscriber numbers and an 01xxx area code has declined rapidly in recent decades.
There were 511 ranges allocated across 56 different area codes in January 1998.
These six areas have a three-digit area code matching the pattern 11x, with a seven-digit subscriber number, and this is known as 3 7 format.
The first three digits of the local number identifies a small area within the town or city.