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'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.

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.   

Quote:

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.