Google has announced that they have extended carrier billing for mobile devices.  Even though it is not that long of list you would have wanted them to hit more countries as of now. I want to see them come with carrier billing for Play Store here in Sweden.  Another option that people seem to want is gift cards and coupons that can be used for purchases.

List of carriers that allows carrier billing as of now

Germany       T-Mobile International, Vodafone

• Italy Vodafone
• Japan Docomo, KDDI, Softbank
• Korea KT, SKT, LGU+
• Spain Vodafone
• UK          T-Mobile International, Vodafone
• US          AT&T, Sprint, T-Mobile

Source: Google