Microsoft has re-released Domain Exclusion for Microsoft 365 Copilot, giving organizations more control over how Copilot uses public web content when generating responses. The capability was previously announced in July 2026, temporarily withdrawn, and is now available again.
Copilot’s ability to surface information from the web is incredibly valuable. It helps users access current information, research topics, and supplement organizational knowledge. However, there are situations where organizations may not want Copilot referencing specific websites or domains due to compliance requirements, content quality concerns, or internal governance policies.
That’s where Domain Exclusion comes in.
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What Is Domain Exclusion?
Domain Exclusion allows administrators to specify up to 1,000 external websites that Microsoft 365 Copilot or Copilot Chat should not use when grounding responses with public web content.
In simple terms, if there are public websites your organization does not trust or does not want influencing Copilot responses, you can add them to an exclusion list. This gives organizations another governance control to help align Copilot with internal policies and trusted-source strategies.
How It Works
Domain Exclusion is not enabled by default. Organizations must opt in and configure the capability through a PowerShell script provided by Microsoft. Download it at https://aka.ms/Copilot/DomainExclusionScript.
Limitations
As of September 16, 2026, the domain exclusion configuration supports up to two levels of subdomains. Additionally, exclusions apply only to web page results used for web grounding. Results from other answer verticals, such as news, might still be cited.
A Growing Copilot Governance Toolkit
The return of this feature is another sign that Microsoft continues to expand the governance toolkit available to organizations deploying Microsoft 365 Copilot at scale.
While Domain Exclusion is a relatively simple control, it gives organizations a practical way to govern how Copilot incorporates public web content in its responses. It’s one more tool that can help organizations build confidence in their AI investments while preparing for more advanced agent and AI capabilities in the future.
At C5 Insight, we help organizations establish the governance, adoption, and enablement foundations needed to scale Copilot successfully. Contact us to start a conversation about your organization’s AI Transformation.