Faxing over VOIP using HP all in one fax products is a challenging thing to push through. This is due to the fact that HP fax products are designed to work with analog fax lines, where continuous signal is transmitted with lesser or no errors. VOIP lines, on the other hand, is digitally transmitted through digital packets and are prone to packet loss errors. Now, when HP fax machines can detect error it will terminate the transmission automatically making it impossible to send and receive faxes. That is why HP claims that they cannot guarantee their fax machines to work with VOIP fax lines. However it may work with certain settings. Check out this HP document for set up your VOIP fax.

