# Using Bluetooth to Auto-Assign Vehicles

If you drive multiple vehicles, SmartMiles can use Bluetooth to figure out which car you are in and assign trips to the right vehicle automatically.

## How it works

Most cars have a Bluetooth system (for hands-free calling or audio). When your phone connects to your car's Bluetooth, SmartMiles detects which device it connected to and assigns the trip to the vehicle linked to that device.

## Linking a Bluetooth device to a vehicle

1. Make sure your phone is paired with your car's Bluetooth (through your phone's Bluetooth settings, not SmartMiles).
2. In SmartMiles, go to **Settings > Vehicles**.
3. Tap on the vehicle you want to link.
4. Tap **Add Bluetooth Device**.
5. Select your car's Bluetooth device from the list of paired devices.

## Tips

- **One device per vehicle.** Each Bluetooth device can only be linked to one vehicle.
- **Device names vary.** Your car might show up as the model name (e.g., "Civic"), a generic name (e.g., "Car Audio"), or something else. Check your phone's Bluetooth settings if you are not sure which name belongs to which car.
- **You can unlink a device** at any time from the vehicle's settings screen.

## How assignment priority works

When SmartMiles assigns a vehicle to a trip, it checks in this order:

1. **Bluetooth detection** — If your phone was connected to a linked Bluetooth device during the trip, that vehicle is assigned.
2. **Default vehicle** — If no Bluetooth device was detected, your default vehicle is used.
3. **No vehicle** — If no default is set and no Bluetooth match was found, the trip has no vehicle assigned.

You can always change the assigned vehicle manually from the trip detail screen.