Is A Separate Phone Number Required For A Fax?

Sorry, I wasn't sure if this was the right forum to ask this question. We still AT&T POTS for phone can we fax using our main phone number? Right now we have a separate phone number for the fax along plus a distinctive ring tone for the fax. Do you need the separate phone number because of those fax tones? I am asking this because its $8 extra a month for that service. Thanks.