London Borough of Sutton, post codes SM, KT, CR
Area code 020 is London. There is no more specific geographic information possible from the information in your question.
This is a code for an area of London but has been written incorrectly. It should read 020 3634
For dialing a telephone number outside your local area.
In what country?
The postal code of Hayes, London is UB3, UB4. The dialing code of the town is 020. The town is located n west London.
628 is an area code for the San Francisco area.
00353 + the area code
In the UK, 01408 is the area code for Golspie.
Yes. But is it not used if you are dialing from within that Area Code.
The dialing code for the USA from the UK is 00 1 The area codes for Houston, Texas, are 713, 281, and 832
01456
This isn't a London code. It is the area code for Brentwood in Essex which is about 30 miles northeast of London.