Microsoft 365 hit by outage knocking out Teams, SharePoint and Excel
Downdetector logged more than 2,400 user reports as Microsoft opened incident MO1437424 and began investigating.
Key points
- Microsoft 365 services including Teams, SharePoint, Excel and the Admin Center went down on the morning of July 23.
- Downdetector recorded 2,403 user reports at 11:11 a.m. ET, well above its normal baseline of 29.
- SharePoint drew 78% of complaints, with Excel at 11% and the Microsoft 365 Admin Center at 6%.
- Microsoft has opened incident MO1437424 in the admin center and says it is investigating.
- The cause is not yet public, and there is no indication so far of a security incident.
Microsoft's cloud office suite fell over on Wednesday morning, cutting off staff at businesses around the world from the tools they use to collaborate and store files.
The problems hit Teams, the chat and video-calling app. SharePoint, which companies use to store shared documents, went with it. So did Excel and the Microsoft 365 Admin Center that IT staff rely on to manage user accounts.
Downdetector logged 2,403 user complaints at 11:11 a.m. Eastern Time on July 23. Its normal baseline is 29. SharePoint took the brunt of it, accounting for 78% of reports. Excel followed at 11%, the Admin Center at 6%.
This lands on an already rough week for Microsoft's collaboration stack. Our earlier story on July 23 found that a memory bug from an infrastructure change has been quarantining legitimate mailboxes since Sunday, blocking email and calendar access.
What is actually broken?
Users cannot reliably reach Teams chats, SharePoint sites, Excel files stored in the cloud, or the admin console. Microsoft has acknowledged the disruption but has not said what caused it.
"We're investigating reports of issues with Microsoft 365 services," the company said, first flagged by BleepingComputer. IT administrators have been pointed to incident MO1437424 in the Microsoft 365 admin center for updates.
| Service | Share of complaints |
|---|---|
| SharePoint | 78% |
| Excel | 11% |
| Admin Center | 6% |
| Total reports at 11:11 a.m. ET | 2,403 |
| Downdetector baseline | 29 |
Is this a cyberattack?
No public evidence points to a security incident at this stage. Microsoft has described it as a service issue. Large 365 outages in the past have usually turned out to be configuration changes or networking faults inside Microsoft's own systems, not intrusions.
That distinction matters, because when Teams and SharePoint go dark together, the first question in most offices is whether someone broke in. Nothing so far suggests that.
Should you worry about phishing?
Yes, if your staff aren't warned. Outages are a reliable backdrop for phishing: criminals send fake login pages hoping panicked users hand over passwords. It's worth flagging to colleagues before anyone clicks a link promising to restore their Microsoft 365 access. Our story on the Helix extortion crew from July 9 is a reminder of how quickly attackers exploit SharePoint disruption.
What should users and IT teams do?
Wait, and watch the admin center. There is no user-side fix for a cloud outage. Restarting Teams or clearing a browser cache won't bring the servers back.
Check incident MO1437424 in the Microsoft 365 admin center rather than relying on social media. Fall back to phone or SMS for anything urgent, and note which conversations need to be re-sent once Teams returns. Avoid working on local copies of SharePoint files without checking sync status first, to prevent version conflicts on recovery.
No timeline for full recovery has been given. This story will be updated as Microsoft provides further detail.
