Forum Discussion
Unified Company Calendar for Mixed Microsoft 365 and Non-365 Users – 2025
Seeking a Shared Calendar Solution for Mixed Microsoft 365 and Non-365 Users
I’m working on a solution to create a shared company calendar that everyone in our organization can view, while keeping editing permissions limited to a few selected individuals.
The challenge:
Some of our team members do not use Microsoft 365, and I’d like them to still be able to subscribe to or view the calendar and receive updates.
Ideally, this should work without requiring full Microsoft accounts.
I initially considered using an ICS-based calendar, but it seems Microsoft 365 Group calendars don’t support sharing via ICS links. I also explored creating a Group calendar as suggested in other threads, but ran into issues making it accessible to external users or those without 365 accounts.
For context, I’m a Global Admin, so I have full access to configure settings in the Microsoft 365 Admin Center and Exchange if needed.
We’re a small business, and our main goal is to have a centralized calendar for vacation schedules and company-wide events. It should be simple to access and maintain, with a focus on collaboration and accessibility across the board.
What I’m looking for:
- A calendar that’s viewable by all, including non-M365 users
- Editable only by a few delegated team members
- Compatible with Microsoft 365, but not dependent on it for basic access
- Any tools, workarounds, or best practices that have worked for others in similar hybrid environments
1 Reply
You can consider this as publishing a shared calendar via ICS\HTML:
- Create a Dedicated Shared Calendar
- Use Outlook desktop or Outlook on the web to create a new calendar (not a Group calendar).
- Name it something like “Company Events” or “Vacation Tracker.”
- Delegate Editing Permissions
- In Outlook, right-click the calendar > Properties > Permissions.
- Grant Editor or Owner access only to selected M365 users.
- Set Default permission to “Reviewer” or “None” to prevent unintended edits.
- Publish the Calendar to Web
- In Outlook on the web:
- Go to Settings > View all Outlook settings > Calendar > Shared calendars.
- Under Publish a calendar, select the calendar and choose:
- Can view all details (for full visibility)
- Get ICS link (for subscription)
- Get HTML link (for browser view)
- Share the ICS and/or HTML link with non-M365 users.
Please note, this method does not require recipients to have Microsoft accounts and works with most calendar apps such as Apple one
