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Find Phone Number
A telephone numbering plan is a system that allows subscribers to make and
receive telephone calls across long distances. The area code is that part of the
telephone number that specifies a telephone exchange system. Telephone numbering
plans assign area codes to exchanges, so that dialers may contact telephones
outside their local system. Normally occurring at the beginning of the number,
area codes usually indicate geographical areas. Together, numbering plans and
their component area codes direct telephone calls to particular regions on a
public switched telephone network (PSTN), where they are further routed by the
local network.
Callers within the geographical area of a given area code usually do not need to
include this particular area code in the number dialed, thereby giving the
caller shorter local telephone numbers. Noticed that this may not be true for
cell phone numbers. Some cell phone/mobile phone carriers still require dialing
the area code even for the same area code. Sometimes the population growth also
introduces two or more area codes even though the physical location are near by.
In international phone numbers, the area code directly follows the country
calling code.
Although the International Telecommunication Union (ITU) has attempted to
promote common standards among nation states, numbering plans take different
formats in different parts of the world. For example, the ITU recommends that
member states adopt 00 as their international access code. However, as these
recommendations are not binding on member states, some have not, such as the
United States, Canada, and other countries and territories participating in the
North American Numbering Plan.
The international numbering plan establishes country codes, that is, area codes
that denote nations or groups of nations. The E.164 standard regulates country
codes at the international level and sets a maximum length limit on a full
international phone number. However, it is each country's responsibility to
define the numbering within its own network. As a result, regional area codes
may have:
A fixed length, e.g. 3 digits in the United States and Canada; 1 digit in
Australia.
A variable length, e.g. between 2 and 5 in Germany and in Austria; between 1 and
3 in Japan; 1 or 2 in Israel.
Or be incorporated into the subscriber's number, as is the case in many
countries, such as Spain or Norway. This is known as a "closed" telephone
numbering plan. In some cases a trunk code (usually 0) must still be dialled, as
in Belgium, Switzerland and South Africa.
Generally the area codes determine the cost of a call. Calls within an area code
and often a small group of adjacent or overlapping area codes are normally
charged at a lower rate than outside the area. Special area codes are generally
used for free, premium rate, mobile phone systems (in countries where the mobile
phone system is caller pays) and other special rate numbers. There are however
some exceptions, in some countries (e.g. Israel), calls are charged at the same
rate regardless of area and in others (e.g. the uk) an area code is occasionally
treated as two parts with different rates.
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