You can connect an unlimited number of scales to your My TANITA Healthcare app (models RD-545 (HR), RD-953 and BC-401 only). However, not all scales can be 'remembered' in the app and a connection will have to be made each time to the desired scale. You can do this by removing the scale you last connected to from your app and restarting the connection with the desired scale. Here you can read the steps on how to establish the connection between your scale and phone/tablet: How can I connect my scale with the My TANITA App?