Lumia store payment.

[Chalanthorn Chanmathikornkul]

Before that, I use carrier billing to purchase things on windows phone.
But if I buy a dual sim phone. How will it work out?

 

[gpobernardo]

With the correct regional settings, you will be asked to choose your billing option (as always). If you've got two SIM cards, with two different accounts, you should be asked to choose which account will be billed.