Android In-App Billing Tax

Question

I've implemented in-app billing in our app. All is working well. However, we're asked if we could determine the exact tax on each purchase to be sent later to a server for real-time tracking purposes, and the sales report from Android Developer Console is only updated once a month (not entirely sure, as according to the information from the site, it's only delayed for 2 days), so that is not an option.

The problem is we're only able to retrieve the price without taxes through the in-app billing API (as also stated in the API documentation).

It seems that the tax charges are based on the country the user entered through the credit card information - and, of course, due to security issues, that cannot be retrieved as well.

Is there another way to determine from which country the user is purchasing from (i.e., the one from his/her credit card). Or better yet, is there a way to simply determine the tax on each purchase?