---
title: Bring your own Twilio number
description: "Connect a phone number you already own in Twilio with its Account SID and Auth Token, so campaigns can call from it and answer on it."
---

<Badge variant="accent">Voice agents</Badge>

**BYOT Phone** (bring your own Twilio) connects a number that lives in your Twilio
account. Callab AI places and receives calls through Twilio on your behalf; the
number, its billing and its compliance registration stay in Twilio.

:::note[Before you start]
In the Twilio console you need the number in E.164 form, and the **Account SID**
and **Auth Token** of the account that owns it. The Auth Token grants full access
to that account; consider a subaccount that holds only the numbers you connect.
:::

## Connect the number

1. **Choose the type**

    Under **Phone Numbers**, choose **Add Phone Number**, then **BYOT Phone**.

2. **Fill in Add Twilio Phone Number**

    **Nickname** is how the number appears in lists and campaign pickers. **Phone
    Number** is the Twilio number with country code, as in `+15555550100`.
    **Twilio Account SID** starts with `AC`; **Twilio Auth Token** is the token
    from the same account.

3. **Add**

    Choose **Add**. The number appears in the list with its provider.

![The Add Twilio Phone Number form.](/media/deploy/byot-twilio-form.webp)

## Fields

| Field | Notes |
|---|---|
| **Nickname** | Free text, up to 30 characters, shown wherever the number is listed. |
| **Phone Number** | E.164, with the leading `+`. Must exist in the Twilio account. |
| **Twilio Account SID** | `AC` followed by 32 hexadecimal characters, from the Twilio console. |
| **Twilio Auth Token** | The account's auth token, at least 32 characters. Stored for placing and answering calls; not shown again. |

## Behaviour and limits

- Outbound calls are placed through Twilio and billed by Twilio as usual; Callab
  AI bills the agent's minutes. See [Billing](/account/billing).
- Inbound calls reach the agent once an
  [inbound campaign](/deploy/campaigns/create-an-inbound-campaign) is running on
  the number.
- Rotating the Auth Token in Twilio breaks the connection until you update it
  here. Open the number's page and choose **Edit**; **Edit Twilio Phone Number**
  opens with the token field empty. Enter the new token and choose **Update**.
- The [Transfer Call](/build/tools/transfer-call) tool can transfer through Twilio
  for calls on this number.

## Verify

- The number is listed under **Phone Numbers** with **Status** `active`.
- Create a campaign on it and place one test call. The call shows in **Call
  Logs** and in the Twilio console's call log at the same time.

## Troubleshooting

- **Add fails.** The SID and token do not belong to the same account, or the
  number is not on that account. Copy both from the console page of the account
  that lists the number.
- **The number rings but the agent does not answer.** No inbound campaign is
  running on it. Check **Launch AI Voice**.

## Related

- [Phone numbers overview](/deploy/phone-numbers/overview)
- [Connect a SIP trunk](/deploy/phone-numbers/sip-trunk)
- [Create an outbound campaign](/deploy/campaigns/create-an-outbound-campaign)
- [Transfer Call](/build/tools/transfer-call)