Methods and system for validating facsimile communications by ensuring that each detected facsimile calling tone is actually a facsimile calling tone that was generated by a sending facsimile device. The method can include establishing a connection between a sending facsimile device and a receiving facsimile device, which was initiated by either the sending facsimile device or the receiving facsimile device. The connection can be utilized for at least one of facsimile communication, voice communication, and a combination of facsimile communication and voice communication. The method can also comprise switching the receiving facsimile machine from a voice-capable mode to a facsimile mode once at least one facsimile calling tone is detected after a first facsimile calling tone is detected while the receiving facsimile device in the line monitoring mode.