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

# SIP and PSTN dial-in/dial-out

> Add phone and SIP connectivity to Daily rooms — dial-in with a PIN, pinless dial-in via webhook, SIP video, dial-out, DTMF, and call transfers.

Daily supports connecting standard phone and SIP participants to video calls, enabling telephony integration for contact centers, conferencing, and voice bot applications.

## Prerequisites

* **Paid Daily account** — add a credit card in the [dashboard](https://dashboard.daily.co/billing).
* **Dial-out approval** — fill out the [dial-out request form](https://forms.gle/Q5eaHLEosuKyzC7BA) to avoid fraud and misuse. Once approved, set `enable_dialout` on your rooms.
* Default limit: `max_sip_pstn_sessions_per_room = 5`. Contact [support](mailto:help@daily.co) to increase this.

<Note>
  We've removed the requirement for a paid-support plan for SIP and PSTN dial-in, it is now available for all pay-as-you-go accounts. You just need to have a credit card associated to your domain.
</Note>

## SIP

Daily supports SIP dial-in and SIP dial-out with the following codecs:

* **Audio:** PCMU, PCMA, G722, Opus (default: PCMU/PCMA)
* **Video:** H264, VP8 (default: VP8)

If a codec is not supported by the remote party, Daily transcodes the stream (transcoding charges apply — see [pricing](https://www.daily.co/pricing)).

Tested with CPaaS vendors (Twilio, Telnyx, SignalWire) and SIP hardware phones (Poly, Cisco).

For full SIP setup details, see the [SIP guide](/docs/guides/features/dial-in-dial-out/sip).

## PSTN phone numbers

### Global dial-in numbers

You can receive PSTN calls without purchasing a phone number. Daily provides global dial-in numbers in 27 countries. Each room gets a unique 11-digit PIN code, generated at room creation and deleted when the room expires.

Free tier includes US and Canada:

* US: +1 (209) 503-8039
* CA: +1 (226) 807-8039

Access to the other 25 countries (including all major European countries, Japan, Singapore, Malaysia, India, China, Hong Kong, Brazil, Mexico) requires a paid support plan. See [this page](./pstn-international-dialin) for the full list of countries and numbers.

### Purchasing phone numbers

Daily's REST API supports [purchasing phone numbers](/reference/rest-api/phone-numbers/buy-number) in the US and Canada (+1). A single number can handle hundreds of simultaneous calls.

A purchased number can can be used for PSTN dialout. However, a number can only be assigned to either PIN dial-in or pinless dial-in, but not both.

## PSTN dial-in methods

Daily supports two PSTN dial-in flows:

* **[PIN dial-in](/docs/guides/features/dial-in-dial-out/pstn-pin-dialin)** — callers dial a phone number and enter a room-specific PIN code.
* **[SIP Interconnect and Pinless dial-in](/docs/guides/features/dial-in-dial-out/sip-interconnect-pinless)** — incoming calls trigger a webhook where you can define logic to route the call to a Daily room without requiring a PIN.

## PSTN dial-out

<Note>
  Dial-out checklist ([once your account is approved](https://forms.gle/Q5eaHLEosuKyzC7BA)):

  1. [Purchase a phone number](/reference/rest-api/phone-numbers/buy-number) (skip if dialing a SIP URI)
  2. [Enable dial-out](/reference/rest-api/rooms/create-room#body-properties-enable-dialout) on the room
  3. Join the room with an [owner token](/reference/rest-api/meeting-tokens/create-meeting-token#body-properties-is-owner)
  4. Dial US/Canada (+1) numbers in [E.164 format](https://en.wikipedia.org/wiki/E.164) (e.g., +16505551212). For international dial-out, contact [help@daily.co](mailto:help@daily.co).
</Note>

Dial out to a mobile or PSTN phone number from within a Daily room:

* [`startDialOut()`](/reference/daily-js/instance-methods/start-dial-out) in daily-js
* [`/rooms/:name/dialOut/start`](/reference/rest-api/rooms/dial-out/start) via REST API

## DTMF tones

Send DTMF (touch-tone) signals during a call — commonly used for IVR interactions:

* [`sendDTMF()`](/reference/daily-js/instance-methods/send-dtmf) in daily-js
* [`/rooms/:name/dialOut/sendDTMF`](/reference/rest-api/rooms/dial-out/send-dtmf) via REST API

DTMF is sent in-band and as an RTP telephone event per [RFC 2833](https://datatracker.ietf.org/doc/html/rfc2833)/[RFC 4733](https://datatracker.ietf.org/doc/html/rfc4733). SIP INFO ([RFC 6086](https://datatracker.ietf.org/doc/html/rfc6086)) is not supported. Receiving DTMF from a PSTN/SIP connection into a Daily room is not yet supported.

## Call transfers

Daily provides two transfer methods. Both methods maintain the original SIP/PSTN connection, meaning the initial caller's connection does not disconnect during the transfer:

* **[SIP Call Transfer](/docs/guides/features/dial-in-dial-out/transfers)** — keeps the original SIP leg anchored to Daily and redirects the far end to a new SIP or PSTN destination. Both connections remain active and billable.
* **[SIP REFER](/docs/guides/features/dial-in-dial-out/transfers)** — hands the call off to the originating SIP system. Daily exits the call entirely. A one-time SIP REFER fee may apply.