---
title: Phone Auth
description: React Native Firebase provides integration with Firebase Phone Authentication.
---

# Phone Auth

Phone authentication allows users to sign in to Firebase using their phone as the authenticator. An SMS message is sent
to the user via their phone number containing a unique code. Once the code has been authorized, the user is able to
sign in to Firebase.

Phone numbers that end users provide for authentication will be sent and stored by Google to improve our spam and abuse prevention across Google services, including but not limited to Firebase. **Developers should ensure they have appropriate end-user consent prior to using the Firebase Authentication phone number sign-in service.**

> Firebase Phone Auth is not supported in all countries. Please see their [FAQs](https://firebase.google.com/support/faq/#develop) for more information.

React Native Firebase provides two separate integration flows:

- **`signInWithPhoneNumber`**: The recommended flow, provides a straightforward API for authenticating.
- **`verifyPhoneNumber`**: A custom flow, gives full control to the developer to implement. Suitable for custom
  authentication flows.

## signInWithPhoneNumber

The `signInWithPhoneNumber` method handles the entire authentication flow, however provides less flexibility over
error handling. Some Android devices may also automatically handle the incoming SMS code and authenticate the user
automatically.

> Whilst testing, make sure you have [whitelisted your device](https://firebase.google.com/docs/auth/ios/phone-auth#test-with-whitelisted-phone-numbers).

**Step 1**: Trigger phone auth

```js
import auth from '@react-native-firebase/auth';

const { confirm } = await auth().signInWithPhoneNumber('+1 650-555-3434');
```

**Step 2**: Confirm code

Once the message has been received, the user will need to input it manually within your login flow.

```js
try {
  await confirm('12345'); // User entered code
  // Successful login - onAuthStateChanged is triggered
} catch (e) {
  console.error(e); // Invalid code
}
```

**Step 3**: Android automatic verification

Some Android devices may automatically verify codes received via SMS. If this happens, the `onAuthStateChanged` method
is triggered, meaning no manual code verification is required.

```js
firebase.auth().onAuthStateChanged(user => {
  if (user) {
    // Stop the login flow / Navigate to next page
  }
});
```

## verifyPhoneNumber

_TODO_ @ehesp @salakar