Microsoft incident EX1550543 affected Exchange Online beginning November 12 and continued into this morning.
What many Microsoft 365 customers may not realize is that Microsoft has a contractual Service Level Agreement (SLA) covering Exchange Online.
Under the October 2026 Microsoft Online Services SLA, Exchange Online service credits are:
Availability below 99.9% → 25% service credit
Availability below 99% → 50% service credit
Availability below 95% → 100% service credit
Microsoft calculates Exchange Online availability using affected user-minutes, so the duration of the overall Microsoft incident does not automatically determine the credit.
And here's the part businesses should know:
Service credits aren't automatic. You have to submit a claim.
Microsoft requires information including the incident details, downtime, affected resources, number and locations of affected users, and errors experienced. Microsoft then determines whether the SLA was missed and what credit applies.
So if your business was affected by EX1550543, don't just dismiss it as another cloud outage.
Check your Microsoft 365 Service Health history, document your impact, and determine whether you're eligible for an SLA service credit.
Cloud providers have SLAs. Make sure you're actually using them.
Microsoft SLA: https://www.microsoft.com/licensing/docs/documents/download/OnlineSvcsConsolidatedSLA(WW)(English)(October_2026)(CR).docx
#Microsoft365 #ExchangeOnline #SmallBusiness #Cybersecurity #BusinessContinuity #SecureSMB
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