TELECOM Digest OnLine - Sorted: Re: NANP Number Lengths

Re: NANP Number Lengths

Linc Madison (
Fri, 23 Mar 2007 03:07:58 -0700

In article <>, Marc
<> wrote:

> I've been told by a UK carier that eleven digit numbers beginning 09
> are in use in Canada and diallable by the public - 1 09x xxx xxxx y.

Categorically false. Within the US and Canada, any customer dialed
string beginning with 10 is a carrier selection code, and none of
those begins with 109. Furthermore, any customer-dialable number
(other than short codes) consists of a 3-digit area code followed by
exactly 7 digits. The sequence is:

*XX service codes, optionally dialed as 11XX (esp. on rotary phones)
101XXXX carrier selection code
1 or 0 trunk code
NXX area code (always [2-9] [0-8] [0-9] )
NXX-XXXX local number

Not all of the elements are used on every call, and local rules vary
as to whether it is necessary to dial 1+NPA or just NPA or neither,
for a given calling destination. In particular, about 2/3 of the US
and all of Canada use 1+ to indicate a toll call, but areas such as
California and New York use it only to indicate that the area code
follows, without respect to local/toll distinctions.

Also, no area codes for any customer-dialable number either begin with
'0' nor have '9' as the middle digit. The N9X range is reserved for
transition to longer numbers, and the 0XX range will not be available
at least until all calls within the NANP must be dialed with the full

> As far as I'm aware, although the 09 number space /is/ used, it is
> only for internal network routing purposes and even then will still
> only contain ten digits.

I'm much less of an expert on this area of numbering, but to my
knowledge, *all* internal routing and billing numbers are fixed ten
digits. I once had a calling card attached to a non-dialable billing
number of the form (NXX) 090-XXXX.

Linc Madison * San Francisco, California * Telecom at Linc Mad d0t c0m
URL: < > * North American Area Codes & Splits
Read my political blog, "The Third Path" <>
US, California, and Washington State laws apply to LINCMAD.COM e-mail.

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