Summary. Fax machines (and computers with fax software) need a landline phone line to fax. VoIP & internet phone lines are not compatible with a fax machine (or computer with fax software). An online fax service does not need a phone line.Aug 9, 2021
How do I turn my phone line into a fax?
To connect your telephone and your fax machine using two separate telephone lines, you connect one end of the cable into the wall jack for your fax line and the other end of the cable into the jack typically labeled “Line” found on the back of the fax machine.