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Dummy Fax Number for Testing

Looking for a dummy fax number because your fax machine isn't working — or you're not sure if it is? The fastest way to find out is to send a test fax to a known-working number and see what happens.

Fax Test Numbers

Send your fax to one of these numbers & see it appear below shortly
(click to copy)

or in international format:

How to test if your fax machine is working

There are a few ways to check whether your fax setup is functioning. Here they are, ranked from most to least reliable.

1. Send to a test fax service

Send a fax to one of the Faxbeep numbers above and check the results online. This confirms your machine can send, your phone line is working, and your document quality is acceptable — all in one step.

2. Call a fax number and listen

Pick up a phone and dial a known fax number. If a fax machine answers, you'll hear a CNG tone — a high-pitched beep repeating every three seconds. This confirms the remote line is active, but it does not confirm your machine can send.

3. Check your confirmation page

Most fax machines automatically print a transmission report after each fax. Look for "OK," "Completed," or a similar status. If you see an error code instead, check the table below.

Common fax error codes and what they mean

Error Meaning What to do
Busy signal The remote machine is in use Wait a few minutes and retry
No answer The remote number didn't pick up Verify the number is correct and try again
Communication error Handshake failed mid-transmission Check line quality or reduce baud rate
No dial tone Your line isn't connected Check the cable and verify the line is active
Memory full Your machine's memory is full Clear stored faxes or print pending jobs

Sending vs receiving: two different tests

A successful send does not prove your machine can receive. These are separate functions that fail independently. To test receiving, you need someone to fax something to you.

Two free options for testing both directions:

  • HP: 1-888-473-2963 — send a fax to this number, and HP's system sends one back to you within about 10 minutes.
  • Canon: 1-855-392-2666 — same idea. Send a fax, receive a reply fax.

Still not working?

If your test fax didn't go through, work through this checklist:

  • Check the cable. Make sure your phone line is plugged into the LINE port on your fax machine, not the EXT port. The EXT port is for a telephone handset.
  • VoIP problems. Voice-over-IP lines often can't carry fax signals reliably. If you're on VoIP, ask your provider whether they support T.38 fax relay. Without it, faxes will fail intermittently or not at all.
  • Country and region settings. Fax machines adjust their behavior based on region. Make sure yours matches your actual country — the wrong setting can cause connection failures.
  • Lower the speed. If faxes fail partway through, try setting the transmission speed to 9600 baud. Slower speeds are more reliable on noisy or degraded lines.
  • Clean the scanner. If faxes send but look terrible on the other end, clean the scanner glass and rollers. Dust and smudges cause streaks and blurry text.

FAQ: Fax Testing & Troubleshooting

The most common causes are: dialing the wrong number format (remember to include the country code for international numbers), using a VoIP line that doesn't support fax, or a busy signal on the receiving end. Try again after a few minutes, and double-check the number format.

A "dummy number" usually means a placeholder or made-up number — these don't actually work. A test number is a real, active fax line run by a service like Faxbeep specifically to receive your test faxes.

If you're calling from the same country as the test number, you usually don't need the country code — just dial the local number. For international calls, always include the country code (e.g., +1 for US, +44 for UK, +61 for Australia).

Use HP's echo service (1-888-473-2963) or Canon's (1-855-392-2666). Send a fax to either number, and they'll send a fax back to your machine. If it arrives, your receive function works.

Usually not reliably. Standard VoIP compresses audio in ways that corrupt fax signals. If your provider supports T.38 (a fax-specific protocol), it should work. Otherwise, you'll need an analog phone line or an online fax service.

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