(Updated) Microsoft 365 Copilot: Admins can upload custom dictionaries for Microsoft Teams meeting transcripts

Admins can upload custom dictionaries for Microsoft Teams meeting transcripts to improve recognition of tenant-specific terminology. This feature requires a Microsoft 365 Copilot license and will be available for Teams on various platforms. Rollout starts in June 2025 for targeted release and mid-July 2025 for general availability.

Updated July 15, 2025: We have updated the timeline below. Thank you for your patience.

We’re introducing the ability for tenant admins to upload a custom dictionary on the Copilot Settings page in the Microsoft 365 admin center. This feature enhances meeting transcripts for Microsoft Teams users by improving recognition of tenant-specific terminology, benefiting both Copilot and Intelligent Recap experiences.

A Microsoft 365 Copilot license is required for the Teams meeting organizer or transcription initiator to enable transcript enhancement using the custom dictionary.

This message applies to meeting transcripts in Teams for Windows desktop, Teams for Mac desktop, and Teams for the web, and Teams for iOS/Android.

This message is associated with Microsoft 365 Roadmap ID 487428.

[When this will happen:]

Targeted Release: We will begin rolling out late June 2025 and expect to complete by early July 2025.

General Availability (Worldwide): We will begin rolling out mid-July 2025 and expect to complete by late July 2025.

[How this will affect your organization:]

After this rollout:

• You can upload a flat list of tenant-specific terms (e.g., acronyms, product names, department jargon) organized by language.
• Only Global Admins or AI Admins can upload or delete the dictionary.
• The dictionary applies to all scheduled Teams meetings across the tenant.
• Users cannot edit the dictionary directly; they must request updates through admins.
• After the feature release date, you can upload or manage the dictionary at Microsoft 365 admin center > Copilot > Settings > Other settings > Copilot Custom Dictionary

[What you need to do to prepare:]

• This rollout will happen automatically by the specified dates with no administrative action required before the rollout. You may want to notify your admins and/or users about this change and update internal documentation.
• Begin collecting relevant terms from internal teams in plain text format. The dictionary will be presented in a flat list format, with the required field Term and optional fields including Sounds like, Long form of the term, and Definition and context.

[Compliance considerations:]

You should collect and upload tenant-specific terminologies that are relevant to the tenant and do not include any confidential, sensitive, or personal information.

Before rollout, we will update this post with new documentation.