When you need to test your fax machine and don't have anyone to send to, dialing a random number might seem like the easiest option. It's not — and it can cause problems you didn't expect. Use a dedicated test number instead.
Fax Test Numbers
Send a test fax or scan to one of these destinations.
Test your printer’s email sending
Send a page using Scan to Email or Internet Fax (I-Fax), then check the result here. No phone line needed.
Why random fax numbers don't work for testing
- Most numbers aren't fax lines. A random 10-digit number will almost certainly ring a phone, go to voicemail, or hit a disconnected line. Your fax machine will report an error, and you won't know whether the problem is your machine or the number you dialed.
- No way to verify delivery. Even if a fax machine happens to answer, you have no way to confirm your document was received correctly. Was it legible? Did all pages arrive? You'll never know.
- You might fax a stranger. Sending an unsolicited document to someone's private fax line is, at best, a waste of their paper and ink. At worst, you could be sending sensitive test documents to an unknown recipient.
- Long-distance charges apply. If the random number you dial is long-distance or international, you'll be charged for the call — even if the fax fails.
What a valid fax number looks like
Fax numbers use the same format as phone numbers because they share the same telephone network. The difference is what answers the call — a fax modem instead of a person.
- US / Canada: +1 (XXX) XXX-XXXX — 10 digits after the country code
- UK: +44 (0XX) XXXX XXXX — length varies by area code
- Australia: +61 (0X) XXXX XXXX
- International format: Always start with + and the country code when dialing from abroad
There's no way to tell whether a number is a fax line just by looking at it. You have to dial it and see what answers.
Better alternatives to a random number
| Option | Confirms sending | Confirms receiving | Free | Results |
|---|---|---|---|---|
| Faxbeep test numbers | Yes | No | Yes | Online in 1–2 min |
| HP echo service (1-888-473-2963) | Yes | Yes | Yes | ~10 min |
| Canon echo service (1-855-392-2666) | Yes | Yes | Yes | ~10 min |
| Fax a colleague or friend | Yes | Ask them | Yes | Varies |
| Random number | No | No | Maybe | Never |
Receiving unwanted faxes?
If you're on the other end — receiving faxes you didn't ask for — here are the most common causes and what you can do:
- Wrong number. The sender may have misdialed. This is the most common cause of unexpected faxes.
- Outdated recipient info. Your fax number may have previously belonged to someone else, and senders haven't updated their records.
- Spam or fax blasting. Unsolicited marketing faxes are illegal in many countries. In the US, you can report junk faxes to the FCC.
- Someone testing their machine. If the fax looks like a test page (generic text, a single page, no cover sheet), someone probably dialed your number while testing their fax machine — possibly through a service like Faxbeep.
To stop unwanted faxes, check your fax machine's manual for number-blocking features, or contact your phone provider about call filtering options.
Privacy note: Any fax sent to Faxbeep is publicly visible for 30 days, after which it is automatically deleted. You can request early removal at the bottom of any fax view page.
FAQ: Random Fax Numbers
Can I use a random number generator to create a fax number?
No. Fax numbers must be real, active telephone lines connected to fax equipment. A randomly generated number won't connect to anything useful — it's no different from dialing a made-up phone number.
What happens if I fax a random phone number?
If a person or voicemail answers, your fax machine will fail to negotiate a connection and report an error. If another fax machine happens to answer, your document will go through — but to a stranger, with no way for you to verify it arrived correctly.
Are fax numbers the same as phone numbers?
Same format, same telephone network, different equipment. A fax number is just a phone line connected to a fax machine or fax modem instead of a telephone. You can't tell the difference from the number alone.
Is there a public directory of fax numbers?
No. Unlike phone directories, there's no public listing of fax numbers. If you need a number to send a test fax to, use a dedicated test service like Faxbeep.
