What do I do if I sell my smart watch or get a new device?
You should perform a factory reset on your Fitbit smart watch. This will erase the app and personal data and delete the cards from the smart watch. Instructions are available on the Fitbit website under How do I erase my Fitbit device?
If you get a new Fitbit smart watch, you can install Fitbit pay on the new smart watch and add your cards.