If your toothbrush does not connect with the Philips Sonicare app, follow the steps below: 
- Make sure that your toothbrush is fully charged.
 - Check that your phone's operating system and the app are updated.
 - Activate Bluetooth on your mobile device.
 - Hold your toothbrush and mobile device close together.
 - Remove your toothbrush from the charger or push the mode button to activate the LED symbols on the handle.
 - Open the Sonicare app.
 
 If your toothbrush does not connect when you open the app, unpair/forget your toothbrush in your phone's Bluetooth settings. Restart the Sonicare app to re-pair your device. Clearing the Bluetooth cache on your mobile device may also resolve connectivity issues.
Note: users of the Sonicare 9900 Prestige toothbrush may also be able to resolve connection issues by resetting the handle.