> ## Documentation Index
> Fetch the complete documentation index at: https://docs.itellico.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# DTMF Controls

> Enable keypad tone support for IVR navigation and caller keypad input during phone calls

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## How DTMF Works

DTMF (Dual-Tone Multi-Frequency) is the signal produced when someone presses keys on a phone keypad. Enable DTMF when a phone-call agent needs to:

* send keypad tones to external IVR systems
* collect caller keypad input, such as menu choices or short account identifiers

<Note>
  DTMF is for phone calls only. Web calls and chat sessions do not have a phone keypad, so DTMF does not apply there.
</Note>

***

## Where To Enable It

**Access:** Open an agent, go to **Call Flow**, and scroll to **Keypad Input**.

<Screenshot light="/images/agent-editor__call-flow-tab-light.png" dark="/images/agent-editor__call-flow-tab-dark.png" alt="Call Flow tab showing the keypad input section with the DTMF toggle" />

Turn on **Enable DTMF during calls**.

<Info>
  DTMF is currently an Alpha setting. The dashboard exposes one toggle; keypad timing, capture mode, clear digit, termination key, and buffering behavior use platform defaults.
</Info>

***

## What Is Supported

When DTMF is enabled, the platform registers keypad tools for the call session. It can send tones to the phone leg and receive caller keypad presses from SIP DTMF events.

For exact-length input, such as "collect 4 digits", the platform uses native fixed-length keypad collection when available. For variable-length or menu-style input, it falls back to the platform's internal collector.

***

## Prompt Examples

Use short, explicit phrasing:

```text wrap theme={null}
"Press 1 for billing, 2 for support, or 3 for sales."
```

After the digit arrives, confirm the meaning, not the mechanism:

```text wrap theme={null}
"Got it — I'll help with support."
```

Use DTMF for short numeric input that is easier to enter than to say:

```text wrap theme={null}
"Please enter the last 4 digits of your account number using your keypad."
```

Confirm safely:

```text wrap theme={null}
"Thanks. I found the account ending in 2457."
```

Do not repeat full sensitive values back to the caller unless your workflow truly requires it.

### Always offer a voice fallback

Not every caller will want to use a keypad.

```text wrap theme={null}
"If you prefer, you can also say the number out loud."
```

That keeps the flow accessible for callers on speakerphone, softphones, or devices with awkward keypad access.

***

## Testing DTMF

<Steps>
  <Step title="Use a phone test">
    Open **Test** on the agent and choose **Phone** so you are testing a real phone leg.
  </Step>

  <Step title="Test caller keypad input">
    Ask the agent for a simple keypad response such as `1` or a short numeric identifier.

    Confirm the agent reacts correctly and the call does not stall if no key is pressed immediately.
  </Step>

  <Step title="Test external IVR navigation">
    If your agent must navigate another phone tree, run a live test against that real number or SIP destination and verify the downstream IVR accepts the tones reliably.
  </Step>

  <Step title="Test the fallback path">
    Intentionally avoid pressing keys once so you can confirm the agent retries cleanly or offers a voice alternative.
  </Step>
</Steps>

## Best Practices

* Ask for one keypad action at a time.
* Offer a voice fallback, such as "You can also say the number out loud."
* Confirm only the safe part of sensitive values, such as the last 4 digits.
* Test the exact carrier, phone number, or SIP route you will use in production.

***

## Next Steps

<CardGroup cols={2}>
  <Card title="Transfer Tools" icon="phone-arrow-right" href="/build/tools/transfer-tools">
    Configure live transfer destinations and downstream call handling
  </Card>

  <Card title="Voicemail Handling" icon="voicemail" href="/build/advanced/voicemail-handling">
    Test phone outcomes such as human answer vs voicemail
  </Card>

  <Card title="Phone Numbers" icon="phone" href="/launch/phone-numbers">
    Set up the phone infrastructure required for live keypad interactions
  </Card>

  <Card title="VAD & Turn Detection" icon="waveform-lines" href="/build/advanced/vad-turn-detection">
    Tune interruption and pause behavior around keypad-driven flows
  </Card>
</CardGroup>