Microsoft outage: what small businesses should do now, and next time
Outlook, Teams and OneDrive went down for hours. Here’s what to do while it’s happening and an hour-long plan so the next outage barely touches your business.
On Thursday afternoon, 12 November, Outlook stopped loading for a lot of people. Within an hour it was clear this wasn't a local problem. Email, Teams invitations, OneDrive, SharePoint and Copilot were all affected, in dozens of countries, and on Friday morning Microsoft was still rolling out its fix.
For most small businesses, Microsoft 365 isn't one tool among many. It's the inbox, the calendar, the shared files and often the login for everything else. So when it goes down, work stops. This guide covers what happened, what to do while it's happening, and how to make the next outage a minor inconvenience rather than a lost day.
What happened
The problems started at around 5.30pm UK time on 12 November. Microsoft said it wasn't a cyber attack. Its explanation was that a large number of servers had become unexpectedly unavailable, which pushed extra load onto the rest of its infrastructure. Its first attempts to fix it didn't give the relief it expected, and services came back gradually as servers were returned to use overnight.
The effects reached well beyond office workers. Government departments in Japan and Singapore reported email problems, and AI assistants that connect to Microsoft 365 couldn't read inboxes or calendars. On Friday morning, UK users were still reporting thousands of problems connecting to Outlook.
The point for small businesses
Microsoft's business services are backed by a 99.9% uptime promise. That sounds absolute, but 0.1% of a month is still about 43 minutes, and a bad day can use a whole year's allowance. Outages aren't a sign that you chose the wrong supplier. Every cloud service has them. What matters is whether your business can keep going when one happens.
What to do while it's down
- Check before you fix. Look at Microsoft's public status page, or Service health in the Microsoft 365 admin centre if you have access. If the problem is Microsoft's, nothing you do on your own computers will help.
- Don't reset, reinstall or reconfigure. Changing passwords, removing accounts or reinstalling Office during an outage usually creates a second problem to solve once the first one is over.
- Be extra careful with emails and texts about the outage. Scammers use big incidents as cover. A message asking you to "verify your mailbox" or sign in to "restore access" deserves more suspicion than usual, not less.
- Tell customers what's going on. A short note on your website, social channels or phone message ("Our email is affected by the Microsoft outage. Please call us on…") stops people assuming you're ignoring them.
- Switch to your backup channel. Phone, a team messaging group, a personal email address for urgent client contact. Whatever it is, agree it now, not during the next outage.
Will you lose emails?
Usually not. When an email can't be delivered straight away, the sender's mail server normally keeps trying for a period, often a day or more, before giving up. Most messages sent during an outage arrive late rather than never. The risk is the ones that don't: a bounced enquiry from a new customer who then tries a competitor instead.
That's why it's worth checking how your website's contact form works. If every enquiry is only sent to an Outlook inbox, an outage can delay or lose it. A form that also saves each enquiry somewhere else, such as a database, a CRM or a simple spreadsheet, means nothing depends on one inbox being up.
How to be ready for the next one
Resilience for a small business doesn't mean a second IT department or duplicate systems. It means knowing where your single points of failure are and having a sensible plan for each.
Know what depends on Microsoft. Make a list. Email and calendar are obvious, but check the less obvious ones: apps you sign in to with your Microsoft account, booking tools that read your calendar, shared spreadsheets your team works from, and AI assistants that connect to your inbox.
Keep the essentials available offline. OneDrive lets you mark folders to always keep on your device, so key files open without a connection. Desktop Outlook can show email it has already downloaded. Decide which files and contacts your team would need on a bad day and make sure they're there.
Keep your contact list outside the system. Staff, key clients and suppliers, with phone numbers, somewhere you can reach without Microsoft: printed, in a phone, or in a separate tool.
Make sure your website doesn't depend on your inbox. Your website should keep working, keep taking enquiries and be the place you post an update when other channels are down.
Write down who does what. One page is enough: who checks the status page, who updates customers, which channel the team uses, and when to switch back.
A one-hour outage plan
1. List everything that relies on Microsoft 365, including logins.
2. Agree a backup channel for the team and one for clients.
3. Save the contacts and files you'd need on a bad day where you can reach them without Microsoft.
4. Check that website enquiries are saved somewhere other than one inbox.
5. Bookmark Microsoft's status page and decide who checks it.
6. Draft the "we're affected" message now, so it's ready to post.
Thursday's outage will be fixed and mostly forgotten within a week. The businesses that spend an hour on this now will notice the next one far less.
Want a second pair of eyes on your setup? We look at how your website, forms and everyday systems fit together, and where one outage could stop the rest. Arrange a free call →
Written on the morning of 13 November 2026, while Microsoft was still rolling out its fix. Details of the outage come from Microsoft's status updates as reported by TechRadar, Cointelegraph and BleepingComputer.
