We know that when portable phone appeared on market, there where not so many phone companies as now. People realized that, having an active life, the phone from home was not useful anymore. So, to stay in touch with other while being outside the house, a cell phone was the perfect thing to have.



As cell phones got more and more numerous, cell phone numbers became numerous as well. Managers from phone companies speculated this opportunity and so people has the option to choose between two or more phone companies to provide the cell serviced they want. And so it appears another issue: how we distinguish a cell phone number from a phone provider by another cell phone number of a different phone company. The managers of the companies thought at that when they saw the number of subscribers, that became bigger and bigger each year.



So, every company decided to have its own combination of numbers at the beginning of the cell phone number, so that everyone know what network provides mobile services for that number. This simple idea divided mobile subscribers into many groups, tagged by the phone company they have chosen.



Taking into account the fact that each company establishes a cost for each mobile service someone uses, now we have to pay attention what calls we make, because, usually, phone calls made outside the network that the caller uses are more expensive than those made in the same network.

In the times we live, every one of us has at least a cell phone number, but the most have two or more. This thing happens because we want to have a cell phone number from each phone company, so that, in the end we reduce the costs of our calls.

In this way, we can have a personal phone number, used to make calls to friends and family and a “professional” phone number, used only inside the company we work, and which has restriction for other number than ones of the work partners. The subscription for this last type of phone numbers it is always or very often paid by the company you work for.

Taking into account the fact that a cell number has at least 8 digits, people memorize easier or harder a cell phone number. So, we always find manners for us to remember better each number. We divide the number into 4-5 groups of digits, usually associated with days of birth, age, the number of the street or even the age of the pet.

There are phone numbers so easy to memorize, that even a child could make a phone call to that phone number. An example is 123456 223344, proceeded by the phone company’s prefix.