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

# Getting started

> Connect a Twilio number to send and receive SMS through Heyy.

SMS in Heyy runs on **Twilio** — you bring a Twilio phone number and account, and Heyy handles inbound and outbound texting through the same [Inbox](/help/inbox/inbox-tour) as WhatsApp, Instagram, Messenger, and Live Chat.

## Before you start

* A **Twilio account**.
* A **Twilio phone number** capable of sending and receiving SMS.

<Tip>
  Twilio bills separately from Heyy — for the phone number itself and for SMS usage. Check Twilio's own pricing before connecting a number you plan to send high volume through.
</Tip>

## Connect the channel

1. Go to **Settings → Channels**.
2. Click **Add Channel**.
3. Select **SMS**.
4. Fill in:

   | Field                   | Description                                                                                 |
   | ----------------------- | ------------------------------------------------------------------------------------------- |
   | **Name**                | An internal label — for example *"Support SMS"*.                                            |
   | **Twilio phone number** | The number you purchased in Twilio.                                                         |
   | **Twilio credentials**  | Your Twilio account credentials, used to authorize Heyy to send and receive on that number. |
5. Click **Create** (or **Connect**).

<Frame>
  <img src="https://mintlify.s3.us-west-1.amazonaws.com/heyy-c8bd5c9e/assets/sms-add-channel.png" alt="Add SMS channel form" />
</Frame>

<Warning>
  **Use a fresh Twilio number for Heyy.** A number already wired into another system (a different CRM, a custom script, another messaging tool) will conflict with Heyy over inbound message handling — messages may go to the wrong place, or webhook configuration may get overwritten between the two systems.
</Warning>

## Compliance

SMS compliance requirements vary by country and use case. In the US, for example, Twilio may require **10DLC registration** before you can send at volume. Check Twilio's own registration requirements for your number's country before relying on it for anything beyond light testing — Heyy cannot bypass carrier-level compliance requirements imposed on the number itself.

## How messaging works

* Inbound texts to your Twilio number appear directly in the Heyy [Inbox](/help/inbox/inbox-tour).
* Replies sent through Heyy transmit via Twilio.
* Contacts are indexed by **phone number** — a text from a new number automatically creates a new contact, and one from a known number attaches to their existing record.

## What SMS is good for

* [Automations](/help/automations/index) for routing, tagging, and team notifications.
* [AI Employee](/help/ai-employees/going-live/channel-and-context) assignment for first-response handling.
* Campaign delivery, where enabled on your workspace — see [Campaigns](/help/campaigns-and-outreach/build/campaigns-tour).

<Warning>
  **Deleting an SMS channel is irreversible.** Inbound messages to that Twilio number will no longer appear in Heyy. Export or back up anything you need first.
</Warning>