There's a few online teething issues being reported by some Xbox One gamers, with Microsoft confirming that a couple of features are temporarily unavailable.
According to the update on Xbox Live Status, certain purchase and content usage features are unavailable ("Affected services: Using prepaid cards or codes for downloadable items or Xbox Live subscriptions"), while some social and gaming features are also currently down ("Affected services: Joining other Xbox Live members in online games. Posting game performance or viewing the performance of other Xbox Live members").
Neogaf users are reporting a variety of different issues, so we booted up and were able to get games on both Forza Motorsport 5 and Killer Instinct. Considering our success it's obvious that these issues aren't affecting all users, but given that the console only launched a few days ago it's hardly surprising that some gamers are experiencing problems while Microsoft optimises the service.
It's also worth noting that similar issues are being experienced in different territories, with Germany, Italy, Spain, and North America all reporting similar issues. Some users have reported up to 16 hours of downtime. When we know more we'll let you know.