***

title: Phone Numbers
sidebarTitle: Phone Numbers
icon: phone
description: 'Inbound, outbound, and phone infrastructure'
----------------------------------------------------------

Atoms provides full telephony infrastructure — buy phone numbers, receive inbound calls, make outbound calls, and integrate with existing phone systems.

***

## Capabilities

| Type         | Description                                      |
| ------------ | ------------------------------------------------ |
| **Inbound**  | Customers call your number, reach your agent     |
| **Outbound** | Your agent calls customers (single or campaigns) |
| **Transfer** | Agent connects to human agents when needed       |
| **SIP**      | Connect to existing phone infrastructure         |

***

## Getting Numbers

**Buy from Atoms:**

* Available in 40+ countries
* Local, toll-free, and mobile options
* Instant provisioning

**Bring your own:**

* Port existing numbers
* Connect via SIP trunk

| Type          | Best For                           |
| ------------- | ---------------------------------- |
| **Local**     | Regional presence, lower cost      |
| **Toll-free** | National reach, professional image |
| **Mobile**    | SMS capability                     |

***

## Call Controls

During calls, agents can:

| Action       | Description                         |
| ------------ | ----------------------------------- |
| **Transfer** | Connect to human or external number |
| **Hold**     | Place caller on hold with music     |
| **End**      | Gracefully terminate call           |
| **DTMF**     | Detect keypad presses               |
| **Record**   | Start/stop recording                |

***

## SIP Integration

Connect Atoms to your existing phone system:

* Twilio
* Telnyx
* Vonage
* Any SIP-compatible provider

***

## Get Started

<CardGroup cols={2}>
  <Card title="Platform" icon="browser" href="/atoms/atoms-platform/deployment/phone-numbers">
    Buy and manage phone numbers
  </Card>

  <Card title="Developer Guide" icon="code" href="/atoms/developer-guide/build/calling/overview">
    Programmatic telephony control
  </Card>
</CardGroup>