As I understand, it this is a list of the all the phone number prefixes for the UK.

• 01
  
• 02
  
• 070
  
• 076
  
• 077
  
• 078
  
• 079
  
• 0500
  
• 0800
  
• 0808
  
• 0844
  
• 0845
  
• 0870
  
• 0871
  
• 090
  
• 091

I was wondering if there was a specification which could tell me how many numbers were allowed to follow each of the suffixes and if such a specification exists; where to find it. Also if there are any prefixes missing, I'd appreciate anyone filling in the gaps.

Also 0551,0555,0558,and 056.

You might find the posting,sticky,titled( Numbering and Pricing Information) by Dave (The Moderator) on this sub forum helpful.

I've not looked, but I think you will find the information you are after on Numbering Policy. This has lists of allocated prefixes and which operator they are allocated to.

Can I ask why you are after this information?

I'm doing phone number validation script for my programming class. My Australian one works and for extra credit I'm looking at doing other countries. I found regular expressions for UK home and mobile numbers, but they don't take into account premium services, free call numbers and such.

You should find the information in the Oftel legacy archives (http://www.ofcom.org.uk/static/archive/oftel/index.htm). I have seen Oftel documents relating to numbering length somewhere in this large archive, but can't recall exactly where at the moment. You'll need to do a bit of searching around - numbering groups / bulletins will be a good place to start, but the info you need is there somewhere, and I believe it is likely to be current.

The old Oftel site, although somewhat disorganized, was far more useful to the end user than the current Ofcom one which simply seems to be a pointless effort.

Your validation will not work (in my opinion) as there are different length numbers available for NGN's (0870, 0845, 0844 & 0800) let alone 01 and 02 Geo's.

The standard may be the NGN prefix plus 7 digits, but it can also be plus 6 digits.

Even for some Geographical numbers it can be difficult as some 5 digit prefix codes normally have 6 digits added but occasionally only have 5 digits.
Look at some of the numbers we have in the database for examples.

Even on the Internet this happens quite often so don't be fooled. Watch out for those where digits have been missed off by people misreading them. On numbers submitted to us, 08700 is the most usual culprit, together with those upto 08709, then comes 08453, 08457, etc.   :-/

wrote on Jul 27^th, 2005 at 8:14pm:

Your validation will not work (in my opinion) as there are different length numbers available for NGN's (0870, 0845, 0844 & 0800) let alone 01 and 02 Geo's....

It probably could be made to work but it definitely wouldn't be easy to do and would be very time-consuming as, like DaveM said, there are a lot of different possible combinations to become a potentially valid number.

Have you emailed BT and asked them do they have a list of STD codes and area codes, etc.  Mention the fact that you are a student and its for an assignment as they may help you more without wondering why you are asking in the first place.

wrote on Jul 27^th, 2005 at 9:22pm:

Have you emailed BT and asked them do they have a list of STD codes and area codes, etc. ...

Ofcom provide this information here. It is in the form of several Excel files.

They have missed the leading zero off, and tell you the length of each number (not including the leading zero). If you use Excel to sort them by the column that lists their length, you should be able to see whats what.

It's not straightforward, and there really isn't a nice pattern to what's 11 digit and whats 10 digit (including leading zero).

All new numbers are 11 digit, with older ones 10 digit. Some older 10 digit numbers were migrated to new codes to make them 11 digit ones. Eg, 0345 123456 became 08457 123456.

Then there's Childline, which uses 0800 1111 and NHS Direct which uses 0845 4647.

Thanks guys, there's a wealth of info in those CSV files. It'll just take some time to go through and then determine an appropriate level of granularity.