Topic summary
area codes
Extracted from the Wikipedia article Telephone numbering plan.
Area code
Area codes are often quoted by including the national access code. For example, a number in London may be listed as 020 7946 0321. Users must correctly interpret 020 as the code for London. If they call from another station within London, they may merely dial 7946 0321, or if dialing from another country, the initial 0 should be omitted after the country code.