Initial update
What we know:
What is affected, including the scope and the customer impact:
What we do not yet know:
Actions underway and who owns them:
Any action the customer needs to take:
When the next update will arrive:
Before you send
Ongoing update
What has changed since the previous update?
What evidence supports the current assessment?
What remains uncertain?
Which action is now the priority?
What does the customer need to know or decide?
Next update:
When the issue is resolved
Confirm the service or process has recovered and how that was verified.
Explain any remaining customer actions.
Record the cause only once it has been established.
Agree corrective actions, owners and dates.
Set expectations for any further incident review or commercial discussion.
Relationship check
Once the immediate issue is resolved, ask what was hardest for the customer.
Use that feedback to improve the next response.