Phone and fax on the same line?
Last Update: August 9th, 2021
Yes, you can have a phone and fax machine on the same line. Adding a fax machine to a phone line means there are some limitations to the abilities of the phone line.
If the fax machine is set to answer manually, you will have to be present at the machine and press “receive” whenever a fax arrives. If no one answers the fax or the phone, the line will just keep ringing.
If the fax machine is set to answer automatically, the fax machine will answer the call after a set number of rings. When people call your phone line, they will be greeted with a fax tone (high pitched squeal) if nobody picks up the phone before the set number of rings.
You can not have voicemail and a fax machine that answers automatically on the same line. You can have voicemail and a fax machine set to answer manually (or for outbound use only).
If the fax machine is set to answer manually, you will have to be present at the machine and press “receive” whenever a fax arrives. If no one answers the fax, the line will go to voicemail (and some people attempting to fax may think that your number is not a fax number).
If the fax machine is set to answer automatically, it will pick up before voicemail answers the call. Alternatively, if the fax is set to a higher number of rings than the voicemail, the fax will never answer the phone line.
Even if the call is a voice call (and not meant for the fax machine), the fax will have no way to transfer the call back to voicemail once the line is answered. The fax machine will answer all incoming calls.
An answering machine and fax machine can exist on the same line with the use of a “TAM” feature on the fax.
The difference between an answering machine and voicemail is that an answering machine is present in a home or office, while the telephone company hosts voicemail.
TAM can check the incoming call. If it is a fax, it will route it to the fax machine. If it is not a fax, it will route it to the answering machine.
In the case of using a TAM, the answering machine would have to be located on the same phone jack as the fax. Sometimes both TAM and answering machine are available as a feature on a fax machine. Other times the TAM is part of the fax and an answering machine can be attached to the “EXT” (extension) port. A TAM can also be purchased separately and placed in front of the fax.
TAM can’t work with voicemail, as it needs to first answer the line to check the type of incoming call. Once the line is answered, the call can’t be handed back to voicemail (which is a service hosted by the phone company).
A computer modem and fax machine can exist on the same line, but only one of them can be set to automatically answer the line if it rings (usually the fax machine).
Both devices cannot use the line at the same time. For example, If the fax machine is in the middle of a transmission and the modem tries to use the line, the fax transmission will fail.
A security system and fax machine can exist on the same line buy only one of them can be set to answer the line if it rings automatically (usually the fax machine).
Just like with a computer modem, both devices can not use the line at the same time. Some security systems regularly call a central location. In some situations, both the security system and the fax machine will attempt over and over to connect, and each time interrupts the other. This situation leaves the line unusable for both devices.
Some security systems have a regular call that is placed (as a type of “call home” to the security company). If this is the case with yours, note the time and avoid faxing during this time.
An online fax service helps as there is no need to maintain an extra phone line or to share a phone line between devices. As well there is no fax machine, paper, or toner to manage, and no phone line to maintain. Most of them work very much like a webmail email account, but for fax.
Some phone companies allow for two (or more) phone numbers assigned to the same phone line. Each number makes a different ring when called. The feature is called distinctive ring.
A fax machine equipped with DRPD (distinctive ring pattern detection) can distinguish between the two types of rings and answer the phone line only when the fax number rings. This way when the regular phone line rings, the call can go to voicemail if there is no answer.
Distinctive ring numbers are relatively cost-effective compared with an extra phone line. Expect to pay US$2-5 per month for the second phone number.
One thing to be aware of with a distinctive ring number is that outbound calls (including from a fax machine) will show up on caller ID as coming from the primary phone number.
Installing a dedicated fax line is an alternative for people that have heavy use of both voice and fax and want to keep their equipment in their office.
With a fax line, there is an entire extra set of phone infrastructure. Each line is used on its own, and if one device is in use, the other device is still completely available.
The downside to a fax line is the cost – expect to pay US$25-30 per month. Adding wiring to a home or office starts in the hundreds of dollars as well.
Virtual offices, mailbox stores, and copy/print shops are all places that can send a fax. Sometimes it is easier to use a local service for the occasional fax instead of installing an extra fax line.
We keep a regularly updated page of places that can send a fax.
- AZ Central – Running a fax machine and voicemail on the same line – A quick summary of how to run both a fax machine and voicemail on the same line. Includes instructions on using a distinctive ring.
- Panasonic Support – How do I operate my fax and answering machine on the same line? They keep interfering with each other – Instructions from Panasonic on how to configure distinctive ring on their products.
- Verizon Forums – Setting up fax and voicemail on the same line – A discussion on Verizon’s support forums on getting fax to work with voicemail. The discussion moves towards getting fax to work with an answering machine.
- CNET Discussions – Coordinating between Phone Line and Fax Line – A forum discussion on how to coordinate a fax machine with a phone line.
- SuperUser – Should a fax machine use a DSL filter? – A forum discussion on whether a fax machine should use a DSL filter (yes it should). It also includes a list of other equipment that might require a DSL filter.
- Houston Chronicle – Can I Hook Up a Phone & Fax at the Same Time? – A quick overview of scenarios where you can hook up both a fax and phone at the same time.