A fax number in the US or Canada has the same format as a phone number: the country code 1, then 10 digits, written NXX-NXX-XXXX. The first three digits are the area code, the next three the central office code, the last four the line number. Toll-free fax numbers start with 800, 833, 844, 855, 866, 877 or 888. Whether the number is printed as (NXX) NXX-XXXX, NXX-NXX-XXXX or +1 NXX NXX XXXX, it is the same number.
The parts of a number
The US, Canada and 18 Caribbean nations share one numbering plan, the North American Numbering Plan (NANP), under country code 1. The Canadian Numbering Administrator describes the format:
“NANP numbers are ten digits in length” and follow “the format NXX-NXX-XXXX”, “where N is any digit 2-9 and X is any digit 0-9.”
| Part | Digits | Name |
|---|---|---|
| 1 | 1 digit | Country code (US, Canada and the other NANP countries) |
| NXX | 3 digits | “numbering plan area (NPA) code, often called simply the area code” |
| NXX | 3 digits | “central office code or prefix” |
| XXXX | 4 digits | “line number” |
Because N is always 2 to 9, an area code or central office code never starts with 0 or 1. A number that seems to have 11 digits after +1, or an area code starting with 1, has been copied wrong.
The ways a number is written
All of these are the same fax number:
(NXX) NXX-XXXX, the usual US style;NXX-NXX-XXXXorNXX NXX XXXX;1-NXX-NXX-XXXX, with the long-distance 1 in front, common for toll-free numbers;+1 NXX NXX XXXX, the international form (E.164: a plus sign, the country code, the 10 digits).
In Faxsure you can type or paste any of them, with or without +1, spaces, dashes or brackets; the app reads the 10 digits and checks that the number is a valid US or Canadian number. Enter the number only, without a 9 or another prefix for an outside line.
Toll-free fax numbers
The Canadian Numbering Administrator lists 800, 833, 844, 855, 866, 877 and 888 as “Toll Free numbers with charges billed to called party”, shared by all NANP countries. The code is part of the number, so copy it exactly: 800 and 888 are different codes.
Some agencies give both a toll-free number and a regular one for the same purpose. The IRS instructions for Form 8802, for example, give one number “within the United States only, toll free” and another for “inside or outside the United States, not toll free”. Our directory of official fax numbers keeps each number with the label its source gives it.
Area codes in the US and in Canada
Most area codes are geographic: each covers a state, a province or part of one. The Canadian Numbering Administrator’s table lists each Canadian area code with its province or region, for example 204 for the “Province of Manitoba”, noted as the “same area as 431/584” with “10-digit local dialling”. Where an area has more than one area code, the area code is needed even for a local number, so always copy all 10 digits.
A +1 number can also belong to one of the Caribbean NANP countries. Faxsure sends to US and Canadian numbers only, so those numbers are not accepted. How to send a fax to Canada from the US covers Canadian numbers in more detail.
Numbers that can’t take a fax
- Pay-per-call numbers. The 900 code is for “Pay-Per-Call numbers with charges billed to calling party”. Faxsure does not send to 900 or 976 numbers.
- Short service codes such as 911 are not fax numbers, and Faxsure does not dial them.
- Voice lines. A number in the right format can still be a phone, not a fax machine. If a person or a voicemail answers, the fax fails; see why a fax fails.