020 is the area code for London.
You cannot determine the location any more specifically than that. Originally, the old outer London numbers (0181) were transferred to numbers starting 020 8xxx, which explains the mistaken belief that numbers in that range must be located in outer London. New numbers are being issued to central London starting with 020 8xxx. Also, with number portability, any specific 020 number could be located anywhere in the greater London 020 area.
The full number will be (020) 8368 xxxx.
The London Area Code is (020).
The Exchange will be identified by the '8368' part.
It is Southgate in the N11 postcode area.
020 8783 covers the Teddington and Hampton areas, west of central London.
Sutton
London is area code 020.
UK area code 020 is London.
A UK telephone number like (020) 84xx xxxx will be in London. You need to state two more digits in order to be able to work out which part of London; eg. (020) 8484 or (020) 8411 etc.
UK area code 020 is London, but there are no valid numbers beginning with 020 4, much less 020 43. Also, the area code for London is just 020, not 020x or 020xx. There are no other UK telephone area codes beginning with 020.
020 is London. 020-3 numbers can be anywhere in London. The operator who "owns" this number is Frontier Systems. Note that the area code for London is just 020, not 0203 or 0207 or 0208.
In the UK, area code 020 is London. A number beginning with 020 8488 could be located anywhere in the 020 London area. It is not possible to specify the location more specifically.
UK telephone area code 020 is London and surrounding areas. It is not possible to narrow down the location any further with the information given. Furthermore, with number portability, any specific 020 number could be located anywhere in the greater London 020 area.
Area code 020 is London. There is no more specific geographic information possible from the information in your question.
Bromley is covered by the area code for London, which is 020.
In the UK, area code 020 is for landlines in London. 84 would be the first two digits of an eight-digit local number.
In the UK, area code 020 is London. There is no area code 0208.
UK telephone area code 020 is London, including both the former "Inner London" and "Outer London" zones. A number beginning with 020 7485 is most likely a BT landline in Kentish Town, but with number portability any particular 020 number could be located anywhere in the greater London 020 zone, served by any local telephone company.