It is sometimes listed on a fax machine or phone as a switch with an option for “T” or “P.”
Almost all telephone networks in the world today use tone dialing. It is the method of pressing buttons and those buttons make a sound. We are not aware of any telephone networks that are not able to use tone dialing (if there are any, we’d love to hear about them).
Pulse dialing is the system used on old rotary phones. While the format is widely supported by traditional landline phone networks, many VoIP phone systems no longer support the format. Many telephone menus (“press 1 for service, press 2 for sales,” etc.) will not be able to understand signals from a pulse phone.
Which one to use?
Any fax or phone with a “tone/pulse” selector should be set to “tone” unless the phone network is rotary (pulse) only.
With some phone networks, there is an additional fee for touch-tone service. For example, Bell Canada (one of the largest telephone companies in Canada) only removed their touch-tone fee in 2015. With this fee, some people opt to use pulse dialing on their phones to try to avoid the touch-tone fee.
Sources and more resources
- BT Care Customer Forums – Solved – Pulse/Tone?? – a discussion in the British Telecom (BT) forums about whether to set a phone to pulse or tone.
- DifferenceBetween.net – Difference between Tone Dialing and Pulse Dialing – a quick entry on the difference in tone and pulse dialing methods.
- Digital Spy Forums – set my home phone to pulse or tone? – another forum conversation on pulse vs tone.
- CBC Business – Bell removes Touch-tone fee from bills, but customers still on the hook – Story of the telephone company Bell Canada removing the touch-tone fee from telephone bills in 2015.