[Bal]

Lots of threads about this

But basically you need a phone with a 3 sim. Your phone needs to be unlocked to any network if you are not already on 3. You need credit and need to apply a All in One bolt on. So for example, buy the £20 bolt on with your credit and you get 3000 minutes to UK numbers, 3000 text and 9gb of data which need to be used in a 30 day period.

Yes you can top using the app. You’d be doing well to run out though! Just make sure you don’t make lengthy calls to US numbers.