A phone prefix is a number made from a combination of digits unique for every telephone service provider in each country in the world. Because of the variety of states and countries over the Globe it would not be enough if we all had the same phone prefix because then each of us would have a phone number made out of probably 20 - 30 - 40 digits and it would be kind of hard to remember your mother's cell number or even your own. So every country has a different telephone / cell phone number depending on the phone service provider you use. Every city has it's own area code, so callers inside the same city don't need to enter an area code, only the ones calling numbers located in other cities of the same country need to enter it.

An international prefixes table was made so anyone trying to call a person outside the country's borders would know what international prefix code and what mobile code to dial before the number of the person they want to call. Some countries have more than one telephone / cell phone network, so every network has to use a different prefix associated to their numbers. So for example let's say you live in the United Kingdom and if you want to call your uncle from Egypt and he has a Vodafone cell number, you need to dial the country's international access code that's +20, then the mobile prefix code "10" followed by his cell number. Note: the "+" is not dialed, it only signifies that first you must dial the international access code, so the number should look like this "20 XXX XXX XXX".



Typical United States dialing plans include:

• internal extension that consists of numbers made out of two, three or four digits

• local numbers that consists of seven or ten digits, the digit 9 may precede the number if required to access an outside line.

• long distance numbers made out of eleven digits, consisting of a 1, then a three-digit area code, then a seven-digit number; the digit 9 may precede if required.

• international numbers of any length starting with 011 and preceded once more by the digit 9 if required.

So every mobile network has it's own prefixes associated to their numbers, for example in Romania there are several mobile phone service providers like Vodafone, Orange, Zapp, Cosmote, RDS.Tel and some of them use more than one prefix for it's network. There is Orange with "74" and "75", Vodafone with "72" and "73", Zapp with "78", Cosmote with "76" and RDS.Tel with "77". The country international access code is "+40" so in order to call a person from Romania using Orange's services you need to dial the country's access code first, then the Orange prefix, then the number of the person you need to call. (e.g., 40 74X XXX XXX). If there weren't any country / network / area prefixes we would have a very hard time on calling anyone.