Well the title of the thread says it all

i'm guessing it's how much to send a fax on a bt line.
well it costs the same as a phonecall to the same number, so whichever tarriff your on you will probably be charged the minimum(as a fax only takes a minute or so) which is usually about 3 or 5p. though depending on your tariff the number that you're sending the fax to will may be free as a part of your included minutes.

I thought it was only voice calls that were 'free', although I wouldn't know how BT could tell the difference

i don't think they can, a fax call is just a voice call with your genitals trapped in a vice.

They must be able some how is they can tell that your using a dial-up internet connection using an 0845 number.

http://bt.custhelp.com/cgi-bin/bt.cf...p_cats=345,350

It really doesn't.

To answer the title... I have no idea how much BT spent on sending faxes last year. I would imagine not very much, as most of their employees use email rather than fax.

the 0845 number would be registered as an ISP so not included. however sending a fax to a geographic number i.e 0161 would cost the same as making a call to that number. as most fax machines are on geographic telephone numbers(except for some large companies) then it is safe to say that they would be included in any call plan the op has set-up.

hopefully BT Support will be able to clear this up for us.

The FAX machine sends specific tones out as it is dialling and shortly after answering to establish that it is communicating with a FAX machine. You can buy boxes that sit on your phone line and detect these tones.

The unit then sends FAX calls to the FAX machine and voice calls to the phone(s) And many FAX machines can do the same. Either using a built in handset or an external socket into which you plug your phone.

So the technology exists to tell FAX from Voice. it just depends on whether it is used or not.

Hi daclick,

A fax call would be priced the same as a voice call, for example if you are on the BT Unlimited Evening and Weekend plan and you made the call after 6pm or during the weekend it would be a zero rated call.

Thanks,
Jon.

So data calls are included too? Why are calls to 0845 charged if they are for internet access, which is also data?

The telephone system does not know what is a data call and what is a voice call. Modems (Modulator/Demodulator) convert the bits into an audible signal that can be sent over the telephone system.

It does know. It doesn't detect the data but it matches the phone number to a list of ISPs.