Microsoft 365 Copilot Notebooks: Support for TXT and RTF files as notebook references

Microsoft 365 Copilot Notebooks will support TXT and RTF files as reference sources starting early July 2026, enabling users to include more text-based content for AI analysis and insights. This enhancement requires no action, maintains existing security policies, and expands Copilot’s data processing capabilities.

[What and Why:]

Microsoft is expanding Microsoft 365 Copilot Notebooks to support TXT (.txt) and RTF (.rtf) files as reference sources. This update enables users to bring a broader range of text-based content—such as transcripts, meeting exports, developer notes, and AI-generated outputs—into a single AI-powered workspace. By grounding Copilot in more contextual information, this enhancement strengthens productivity and enables more comprehensive insights, summaries, and content generation.

[Rollout Schedule:]

• General Availability (Worldwide): Rollout begins early July 2026 and is expected to complete by mid-July 2026.

[Impact on Your Organization:]

Who is affected: Users with access to Microsoft 365 Copilot Notebooks

Platforms/Services:

• Microsoft 365 Copilot
• Copilot Notebooks

What will happen:

• Users can upload and use TXT (.txt) and RTF (.rtf) files as notebook references.
• Copilot can analyze and use content from these files alongside other supported formats.
• The feature will be available by default once rolled out.
• Existing Microsoft 365 security, compliance, and data governance policies continue to apply.
• No changes to existing workflows—this is an additive enhancement.

[Action Required/Recommendations:]

No action is required.

Recommended actions:

• Inform users about support for TXT and RTF files in Copilot Notebooks.
• Update internal training or adoption materials to reflect expanded file support.
• Review internal governance policies if needed to ensure appropriate use of text-based content in AI workflows.

[Compliance considerations:]

Consideration	Explanation
Does the change provide end users any new way of interacting with generative AI?	Users can now include TXT and RTF files as reference sources in Copilot Notebooks, enabling Copilot to analyze and generate responses based on additional unstructured text inputs.
Does the change alter how existing customer data is processed, stored, or accessed?	Content from TXT and RTF files added to notebooks will be processed and accessed by Copilot alongside existing reference files to generate insights and responses.
Does the change introduce or significantly modify AI/ML or agent capabilities that interact with customer data?	Copilot’s AI capabilities are extended to interpret and reason over TXT and RTF file content within notebooks, expanding the range of data sources used for AI-driven outputs.