What is Dual Tone Multi-Frequency (DTMF)?

Dual tone multi-frequency (DTMF) is a technology used with touch-tone phones, best known to users as the sound made when pressing a number key. It signals the phone company that you want to make a call and sends a command to the switch. It does this by sending two tones for every number pushed - one high frequency and one low frequency.

Dual tone multi-frequency has an important use in call centers, as many interactive voice response (IVR) systems use DTMF as a way for callers to navigate their menus. An IVR is the front end of the phone call that greets the caller and provides them with menu options. By using dual tone multi-frequency, a caller simply needs to push the number on a keypad that corresponds to the number of the menu option. For example, the IVR might say, "Press 1 for claims," and by pressing one the caller will be connected to a claims representative.

With dual tone multi-frequency (DTMF), callers can also key in account numbers or order numbers, which can then be passed to the service agent to get a jump start on solving the caller's issue.

DTMF can be effective to use with IVRs when the menu options are straightforward or when the caller needs to enter a long number. Whether or not it's the right solution for a specific call center will depend on their business needs.