# Custom Id

You can set a custom id in order to track/target users with id coming from different platforms.

To set a custom id:

```dart
MBAudience.setCustomId('CUSTOM_ID');
```

To remove it:

```dart
MBAudience.removeCustomId();
```

To retrieve the current saved id:

```dart
String customId = await MBAudience.getCustomId();
```