Microsoft 365 Outage: What Businesses Should Do When Outlook and Teams Go Down

When Outlook and Microsoft Teams go down at the same time, businesses should confirm the outage, switch to a backup communication channel and prioritise work that cannot wait. The November 2026 Microsoft 365 outage showed why these decisions need to be made in advance. An outage can interrupt the same tools employees use to report the disruption, reach decision-makers and update customers. Reuters coverage of the Microsoft 365 outage

What happened during the Microsoft 365 outage?

On 12 November 2026, a widespread Microsoft 365 outage disrupted Outlook and Teams, with problems reported into 13 November. Affected users had difficulty accessing mailboxes through Exchange Online, the cloud service that supports email and calendars for many organisations using Outlook. Microsoft said some servers became unresponsive again after they were returned to service and began receiving traffic. It tracked the broader Microsoft 365 disruption under incident MO1550821. Microsoft incident updates archived by the University of Pennsylvania

For businesses, the impact depends on which processes rely on those services. A customer support team may lose access to its shared inbox, an operations team may struggle to reach the person authorised to approve a change, and employees may have trouble finding the meeting details for an incident call. Where email and messaging share a provider, each team needs a way to reach the people who can keep essential work moving.

What should businesses do in the first hour?

1. Confirm the outage and record what is affected

Ask an IT administrator to open Health → Service health in the Microsoft 365 admin centre. Check whether Microsoft has reported an incident affecting your organisation, record the incident reference and note which teams and services are experiencing problems. If the admin centre is inaccessible, check the public service status page and continue collecting reports internally. Microsoft service health guidance · Microsoft service status

2. Move incident communications to an approved backup channel

Activate a channel employees can reach even if their Microsoft 365 account is unavailable, such as an approved SMS alert system or a phone call tree. Name the incident lead, identify where employees should report problems and say when the next update will arrive. Keep an accessible copy of essential contact numbers, with access limited to the people who need them.

3. Decide which work needs to continue

Prioritise urgent customer enquiries, time-sensitive approvals and operational handovers. Assign someone to each critical workflow and specify which decisions can be made by phone or through another approved system. If a payment or other sensitive approval moves to a backup channel, follow the established verification and authorisation procedures. Keep a record of decisions and actions for reconciliation after recovery.

4. Tell customers how to reach you

If a shared inbox or support channel is affected, publish an update through a channel customers can still access, such as your website or customer status page. Say which service is affected, give an alternative route for urgent enquiries and state when you will update them again. Use the same message across customer-facing teams so callers and website visitors receive consistent guidance.

What should teams check after Microsoft 365 recovers?

Test the workflows people depend on. Confirm that staff can send and receive external email, open shared mailboxes and reach the right colleagues in Teams. Check pending approvals and messages that may have failed or remained queued. Assign owners to missed requests and reconcile any decisions recorded through backup channels.

In the incident review, ask which workflows stopped, which backup arrangements worked and how long it took to reach the people who could make decisions. Use those findings to update the continuity plan and run an exercise in which both Outlook and Teams are unavailable. GLOMACS covers continuity planning, crisis communication and recovery in its Emergency and Crisis Management Training Courses.

How can businesses prepare for the next cloud outage?

Map each essential workflow to the services it depends on. Check whether its backup communication channel, contact directory or approval process uses the same Microsoft sign-in or infrastructure. Test whether staff can access the alternative during an outage and give each critical process an owner who can decide when to switch to it.

Review these dependencies with IT, operations and risk teams so that supplier risk assessments reflect what would actually stop if a cloud service became unavailable. GLOMACS explores risk assessment and oversight in its Corporate Governance, Compliance and Risk Management Training Courses.