connect your phone to the fax machine port!

You can't use them in parallel. They have to be used as Master-slave. Yes, it is sometimes inconvenient.

If you got an answer machine in parallel to the fax, you may enter voice mail earlier than fax machine's setting.

You can use fax/phone in parallel, set fax to "wait one ring" to accept fax ... now you can't get voice call now.


So the only way is to link them in series.