It looks like Indian carrier Idea has enabled carrier billing for Windows Phone, which allows customers to purchase digital content from the Windows Phone Store with their phone balance. Several users on our forums have already confirmed that the option is now working for them, and if you're an Idea customer, head on over to the payment options on your phone to check if it is available for you.
Based on the discussion in the forums, it looks like Idea is the only carrier in the country that has the feature enabled. How many of you are interested in seeing carrier billing come to other cellular providers in the country? Let us know in the comments.
Source: Windows Central forums
Thanks Apurva for the heads up!