Having used the HP Fax Test line to test fax machines for many years, it seems to no longer work (last tested on December 17, 2024). 🙁

Normally, you would send a single-page fax to the HP Fax Test line at 1-888-HPFAXME (1-888-473-2963) and about 5 to 10 minutes later you receive a fax back from HP, confirming that end-to-end fax communication is working correctly.

However, it seems the fax-back part of the service is defunct, at least for now. You can still send a fax and it will be accepted, but sadly no fax is ever sent back. This makes it useless as an end-to-end test.

Thankfully, you may still use Canon’s Fax Test line and it works just fine (last tested on December 17, 2024). Send a single-page fax to the Canon Fax Test line at 1-855-FXCANON (1-855-392-2666) and within a minute or two you will receive a fax back to verify the end-to-end communication. 😃 I would recommend that you add this fax number to the machine’s address book for future use.

Another alternative that isn’t quite as simple is from T38Fax.com (last tested on December 19, 2024). You start by visiting their ECM (Error Correction Mode) self-test page, enter your info, and a fax arrives within a couple minutes. Then you turn around and send that printed fax to the number on the page and after a few more minutes they will send an email letting you know whether the ECM feature is working on your fax machine. So it is an end-to-end test but not quite as quick, starts at the far end first, and requires you to enter a valid email address (use a temporary email address if this concerns you).

Hopefully this has helped you in some way. Happy faxing!