The more senior among us will recall the old "01" code which was replaced by 020.
There are 3 variations of the London phone number 020 prefix which are:
- 0207
- 0208
- 0203
The 0203 code is the new kid on the block and covers all of London - the 0207 and 0208 codes originally had a geographical split.
All of the codes are available as "local numbers" which means that UK businesses can use them to give the appearance of being a London based company.
OFCOM authorised resellers include DBS.
The 020 code will be sufficient to supply new London numbers for many years to come according to this article.