Fax number checker

Choose the country, type the number, and find out at once whether it is ready to use.

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A number that can take a fax is a landline written the way its country expects. In Canada, for instance, it is three area-code digits and then seven more, as in (604) 555-0182. This free checker applies the test the CaptainFax sending form uses for Portugal, Italy, Spain, Germany, France, Belgium and Canada. It catches cell numbers and doubled country codes, and gives you the international form.

Check a number

For example 5145551234 (10 digits: a three-digit Canadian area code plus seven digits, without the leading 1; US and unassigned area codes are refused)

Why a wrong digit costs you a retry

When a fax does not go through, the document is rarely the culprit. More often the number was slightly off: a digit lost when copying from a letterhead, a country code pasted on top of one already there, or a cell number taken for the office line. The call then connects to no machine at all, and after a few attempts the send fails.

Each country has its own conventions. Canadian numbers run ten digits with no leading zero, and a 1 in front is only the long-distance prefix. Belgian landlines carry nine digits after the initial 0, and cell numbers start with 04. Italy is unusual because its 0 stays when called from abroad; for Belgium, France and Germany it falls away. The checker follows these rules and returns two versions: the national format for the CaptainFax form, and the E.164 format that most fax equipment and software expect.

It checks how the number is written rather than whether anyone is on the other end, so a properly formatted number might be disconnected or ring an ordinary phone. When the document is important, such as an IRS form or a prescription for a pharmacy, get the number from the organization’s official website, or from the most recent letter you received from it.

Fax number checker FAQ

Is the number I type saved?
No. It is analyzed when you click and then discarded. No fax goes out and nobody calls that number.
Why does the checker reject cell numbers?
To send a fax, the destination must be a fixed line wired to a fax server or to a fax machine. A cell phone can’t make sense of fax tones, so the call would end at a ring or voicemail greeting and never yield a printed page.
Does a green result guarantee delivery?
It guarantees the number is correctly written, which removes most causes of failure. The line must also be active and connected to a machine that is on. If a send still fails, check the number with the recipient.

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