The purpose of the country code?

Answer 1

The purpose of the telephone country code is to efficiently route international calls, while allowing each country to have an internal numbering plan meeting its specific needs.

To dial an international telephone call, dial the appropriate international access prefix. On a GSM mobile phone, just use the plus symbol (+), and the network will automatically substitute any required prefix(es). Otherwise, the prefix depends on the country from which you are calling. Then dial the country code (a one-, two-, or three-digit number, never beginning with a zero), the city or area code (if any), and the subscriber number.

For example, to dial from New York City to London, you might dial 011 44 20 7496 0123.

To dial from London to New York City, you might dial 00 1 212 555 0123.

To dial from Sydney to Tokyo, you might dial 0011 81 3 0000 0000.

To dial from Tokyo to Sydney, you might dial 010 61 2 0000 0000.

[all example numbers shown above are fictitious]

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)