add phone to my o2 app

[bayhead]

I have a spare payg phone for the car and want to be able to top it up from my o2 app. How do i add the phone to the list of my devices. Thanks.

[gmarkj]

You need to do it online, not through the app.
Log in to your main account, and then look for the option to bring in other products and services and follow it through.