What do you call the different parts of a phone number?

Ekene A August 15, 2014
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How are mobile network numbers and their names formatted?

Let me use MTN Nigeria (a mobile network provider in Nigeria) as example. I will use two numbers as examples:

local = 0-803-5002249 international = +234-803-5002249
local = 0-706-0552680 international = +234-706-0552680

Now on these two numbers, they have “country mobile dial code” which are “0” for local and “+234” for international.

They have the next 3 digits numbers which are “803” and “706” respectively.
And the next 7 digits numbers which are “5002249” and “0552680” respectively.

Now my questions are, The first set of numbers, what are they called (I called them “country mobile dial code” but am not sure)? And what keyword will I use to know the local part of that number?

For any country from search engine? like USA is “1” and Nigeria is “0”, if I want
to know local mobile dial code for other countries which keyword will I use to search it?

Secondly, what is the name for the second part of the numbers? I thought it might be “Network Identification Number” but am too not sure. And what keyword will I use to know them from a search engine? like MTN Nigeria ( a Mobile Network Provider in Nigeria) has numbers like 803, 806, 801, 703 etc on that section of the mobile number, what if I want to know that of USA AT&T or others?

Thirdly, do all the Mobile Network Providers in the world have the digits of their last set of number to be 7 digits or is there any one longer or shorter than 7 digits?

Please somebody help me with these for I have been searching for it but no success, and it might be that am using wrong keywords.


  1. Oron J
    August 15, 2014 at 7:39 pm

    First of all, the names of the parts. Using your first example:
    +234: "International code" or "country code". Within certain contexts they might also be called "dialing codes" to differentiate them from, say, postcodes (see for example http://www.worldatlas.com/aatlas/ctycodes.htm)

    803: "Area code" (in the UK also "STD code")

    5002249: phone number

    The 0 at the beginning is a "prefix" or a "long-distance prefix", but I don't think either the name or how the prefixes are used is entirely standard across the globe.

    There's not really a difference between mobile numbers and landline ones apart from the fact that the mobile numbers are obviously allocated by networks, not areas!

    Not all phone numbers (mobile or otherwise) are the same length, or at least not in all countries. I've seen mobile numbers shorted than 7 digits, but never seen ones longer than that. Perhaps another reader has seen longer ones?

    • Jan F
      August 15, 2014 at 11:49 pm

      In most cases 7 digits is the norm as this basically allows 9.999.999 customers which you first have to reach as a provider to get in "trouble".

      For mobile PBX systems it's usually 8 or 9 digits, with the last 2 or 3 digits being the extension e.g. "0123/ 123 456 xx" or "0123/ 123 456 xxx"

      But the mobile market has changed over time so really anything between 6-10 numbers can be expected.
      Technically you can take your full number to another provider so even the "network code" doesn't have to be your actual network.
      Equally, you can technically take your full business number with you (assuming your former employee allows it) and then you might have a 8, 9 maybe even 10 digit private phone number.

    • Bruce E
      August 16, 2014 at 7:12 am

      In the US and Canada, the structure of a phone number falls under the North American Numbering Plan whether is is a landline or cellular. Everything after the country code/international dialing code is subject to this format. So, the structure would be defined in the following format: NPA-NXX-YYYY. The NPA is the Numbering Plan Area aka area code. Not all NPAs are used having special purposes such as the ERCs (easily recognizable codes) having the same 2nd and 3rd digits (888 for toll-free, for example) and the X11 numbers that are not used as area codes at all (there are no other digits after the code, such as 911 for emergency services). The NXX defines the specific exchange or central office inside the NPA. The last 4 digits denote the specific subscriber line at that exchange.

      With landlines, the exchange an individual subscriber was tied to was due to geographic location. Many small towns would share a single exchange and larger urban areas would have multiple exchanges to service all of their users. A user's exchange would almost always be the one physically closest to them. With the advent of cell phones, a user may now have a (mobile) phone number where their physical location isn't even in the same NPA much less being tethered to the closest exchange.

    • Oron J
      August 16, 2014 at 8:12 am

      Thank for the extra info, Jan and Bruce - I've learned something! Regarding number portability, this in not universal, and different countries have different rules. Clearly it's the direction of travel though!