Trouble logging into Microsoft services? You're not alone.

If you've had some trouble signing into any Microsoft services today, you're definitely not alone. Microsoft has acknowledged an issue with its authentication infrastructure that is impacting the ability for users to access Microsoft 365 services across the board.

From the Microsoft 365 status page:

User impact: Affected users are unable to authenticate to and access Microsoft 365 services.

Current status: We've received reports of an issue affecting access to Microsoft 365 services. We've identified a degraded portion of infrastructure that manages authentication requests and have restarted that infrastructure to mitigate impact.

According to Microsoft, the issues started cropping up around 4:15 p.m. ET / 9:15 p.m. UTC. Down Detector, a site that reports on outages for a number of major web services, is also showing a spike on issues for Microsoft services ranging from Office 365 to Outlook, Skype, OneDrive, SharePoint, and more.

Updated January 29 at 6 p.m. ET: Microsoft has released further details on the status of its services and the impacted services. From Microsoft:

Customers that have their authorization cached are unaffected by this issue, and new authentications are succeeded approximately 50 percent of the time and rising.

Dynamics 365, LinkedIn, and other services that leverage Azure Active Directory (AAD) are also affected by this event.

Current status: We've moved services to an alternate network provider and performed numerous targeted service restarts. Our telemetry indicates that service availability has improved significantly and most authentication requests are succeeding; however, we still are observing residual impact to some services. We're working to develop a remediation strategy for all remaining impact.

If you're experiencing problems accessing Microsoft services, there's not much you can do other than wait until the authentication issues are cleared up. Microsoft is expected to provide further status updates throughout the day.

Thanks to @hoyty for the tip!