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

# IP whitelisting and TLS

> TLS and IP whitelisting requirements for Phonovation APIs, webhooks, delivery receipts, and incoming SMS.

Phonovation supports only **TLS 1.2** for API and callback connections. Your API clients and callback endpoints must be able to negotiate TLS 1.2.

## Services covered

The TLS 1.2 requirement applies to every Phonovation integration:

| Service                  | Connection                                                |
| ------------------------ | --------------------------------------------------------- |
| APIs                     | Your application connects to a Phonovation API            |
| Webhooks                 | Phonovation sends SMS processing results to your endpoint |
| Delivery receipts (DLRs) | Phonovation sends delivery results to your callback URL   |
| Incoming SMS             | Phonovation relays incoming messages to your endpoint     |

Connections that cannot negotiate TLS 1.2 will fail.

## IP whitelisting

If your network or firewall requires IP address whitelisting, whitelist the following address:

```text title="Phonovation IP address" icon="network-wired" theme={"dark"}
83.71.142.253
```

This is Phonovation's only IP address for API and callback traffic, including webhooks, DLRs, and incoming SMS relays.

<Note>
  You only need to add this address if your infrastructure restricts connections by IP address.
</Note>

## Customer IP addresses

Phonovation does not whitelist customer IP addresses on its side. You do not need to provide your public server, firewall, or NAT IP address to access Phonovation APIs or receive callbacks.