catj

Is there any thought being given to fix the number lists such that numbers are returned in their correct format even if input in the wrong format?
That is, if the database contains a number like 0207 2343456 to show it on the website like 020 7234 3456 instead?
Taking "British Gas" as an example, and just the 01/02/03 column, there are three numbers in the wrong format in the 'main database' list and at least a further 30 in the wrong format in the 'unverified' list.
In many cases, there is multiple repetition, with e.g. 023 8005 1003 potentially being listed again as 0238 0051003 and 0238 005 1003 and 0238 0051 003 and 02380 051003 and 02380 051 003 and 02380051003. In this case, only 023 8005 1003 is the correct format.
The UK numbering system is quite complex. Here's a quick summary:
Local numbers can be 6 or 7 or 8 digits long.
The code can be 4 or 3 or 2 digits long, after the initial zero.
The area code and number is 11 digits in total, including initial zero.
There are very few exceptions.
Depending on the area code, the numbers are formatted in a very specific way, but it is one that is fairly easy to remember:
Birmingham (0121), Edinburgh (0131), Glasgow (0141), Liverpool (0151), Manchester (0161), Tyne and Wear/County Durham (0191):
Numbers with area code like (01x1) are written: (01x1) xxx xxxx
Leeds (0113), Sheffield (0114), Nottingham (0115), Leicester (0116), Bristol (0117), Reading (0118):
Numbers with area code like (011x) are written: (011x) xxx xxxx
London (020), Southampton and Portsmouth (023), Coventry (024), Northern Ireland (028), Cardiff (029):
Numbers with area code like (02x) are written: (02x) xxxx xxxx
Rest of the country (01xxx):
Numbers with area code like (01xxx) [but not including (01x1) or (011x) codes] are written: (01xxx) xxxxxx
There are a small number of exceptions where the number part has only 5 digits. These are usually written: (01xxx) xxxxx
The brackets around the area code are *optional*.
To summarise:
If the number starts 02x the number part is 8 digits long (grouped as xxxx xxxx).
If the number starts 01x1 or 011x the number part is 7 digits long (grouped as xxx xxxx).
Most other numbers are written 01xxx xxxxxx (6digit number), with a very few as 01xxx xxxxx (5digit number in very rural location).
It would require only a small number of 'regular expressions' to parse and fix the data so that it can be displayed in the Ofcomapproved format.
