Microsoft 365 Copilot for Security uses Security Compute Units (SCUs) to determine available processing capacity for AI-driven operations. Each SCU represents a fixed amount of compute resources for handling Copilot for Security prompts and plugin interactions (like Sentinel).
When a notification appears stating that "SCU usage is nearing the provisioned capacity limit," it means that the organization's current SCU allocation is insufficient for ongoing demand. To restore full response functionality, the tenant admin (or authorized role) must increase the number of provisioned SCUs.
Microsoft documentation states:
"If Copilot for Security indicates that requests cannot be processed due to SCU capacity, increase your provisioned SCUs in the Microsoft 365 admin center or Azure portal to meet demand." The other options do not resolve the issue:
* Opening a second session does not add capacity.
* Waiting does not guarantee SCU availability.
* The Optimization Workbook relates to Sentinel performance, not Copilot SCU allocation.