A recent security change to the Xbox Live service may have impacted users online purchase experience. Currently the video marketplace service and related content is only available to consumers in the United States. Although we will continue to work on providing content and rolling out the service in other markets, US Marketplace offers will be restricted to the US only. This means that the credit card associated with your account is required to match the billing address and country your account is set up in. Note that we are not banning any of these Xbox Live accounts, as they can continue to use pre-paid subscription cards and Microsoft Points cards.

Customers wanting to check the billing information on their account can do this on their console or by signing into Xbox.com with your account and then go to MY XBOX-> MY PROFILE then to BILLING AND CONTACT INFORMATION.

We also realize that there may be a small number of international users that were impacted by this change that have a legitimate reason for why their billing location does not match their account location. We are working to deal with these exceptions on a case by case basis and are working on a solution for these consumers.

News-Source: http://www.majornelson.com