When I try to register my POGO, it tells me it's not a valid serial number. Permanently deleted user June 27, 2018 21:28 Updated Make sure you're using a proper POGO serial number. They have six digits starting with "21". Related articles Registering a new POGO account POGO System Overview Video Why do I have to enter email and password to use the app? POGO Bluetooth Can I still use POGO if I don't own a smartphone?