To Ogwen
1. Northern Ireland has a three-digit area code (028). So does Wales (029), although only Cardiff currently uses the new-style numbers starting 02. Coventry, Portsmouth, Southampton also have three-digit area codes (which will eventually be shared with other locations).

2. "0207 and 0208" do not cater for different areas. When London numbers were changed, all existing 0171 numbers had a 7 added to the local number, but since then 020 7xxx xxxx numbers have been assigned to "Outer London" customers and vice versa.
(Vice Admiral Sir Charles Cockbrush KCB MBE DSO, who is finding it increasingly difficult to log into b3ta.com wants to duck your aunt and kick your puppy, Fri 2 May 2008, 14:23, Reply)