After importing events in classic outlook using a CSV to a shared calendar, only the importer can see the event

Hello Austin Bigge

First, I recommend reviewing the AI‑generated response on your post, as it already highlights several key points that align closely with my own understanding of the issue.

In addition, I wanted to share a relevant Microsoft thread where the same behavior is documented: Only owner able to import CSV into shared calendar?

Based on this and other reports across Microsoft Q&A and community forums, I think this behavior is expected. CSV calendar imports are designed for personal calendars in Classic Outlook. Only the mailbox owner can reliably import calendar data into their own calendar. When a delegate (even with Full Access) imports a CSV or similar file into another user’s or a shared calendar, the import may silently fail or appear only to the importer.

Additionally, New Outlook does not officially support direct CSV imports into calendars, which further contributes to the inconsistent behavior you’re seeing.

To work around this, you may consider the following options.

Option 1: Convert the CSV to ICS (recommended)

Convert the Excel/CSV file to an ICS format, then in Classic Outlook open the employee’s calendar, go to File > Open & Export > Import/Export, choose Import an iCalendar (.ics) file, and select Import (not Open as New). In most cases, ICS imports preserve calendar ownership more reliably than CSV.

Option 2: Have each employee import their own file

Share the CSV with each employee and ask them to switch temporarily to Classic Outlook, import the file into their own calendar, and then switch back to New Outlook.

As an additional quick check, you may also try enabling shared calendar improvements in Classic Outlook on the importer’s device (File > Account Settings > Account Settings > double‑click the Exchange account > More Settings > Advanced > enable “Turn on shared calendar improvements”, then restart Outlook). After re‑importing a test file, it’s also a good idea for the employee to verify the calendar in Outlook on the web to rule out a client‑side rendering issue.

Please feel free to try the options above and let me know how it goes, or if you have any questions. I’m happy to help further.

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The described behavior is consistent with limitations and issues around shared calendars and how Outlook handles items that are created or removed indirectly, especially when mixing Classic Outlook, New Outlook, and shared calendars.

Key points from the scenario and context:

• Events created directly (not via CSV import) appear correctly for the shared calendar users.
• Events imported via CSV into a shared calendar only appear for the importer.
• Inviting the user to those imported events causes them to delete themselves.
• There is known problematic behavior when shared calendars are removed or manipulated, where events can be deleted on the owner’s calendar as well.

Given the available information, there is no supported or documented method in the context that guarantees reliable population of other users’ shared calendars via CSV import into Classic Outlook in this mixed Classic/New Outlook environment. The behavior strongly suggests this is an unsupported or buggy path rather than a configuration issue.

Practical guidance based on the context:

1. Avoid using CSV import into shared calendars for this workflow.
2. Use normal calendar sharing and direct event creation or invitations instead, which is confirmed to work in the environment.
3. If bulk creation is required, use a supported programmatic approach (for example, via Microsoft Graph for shared/delegated calendars) rather than CSV import to a shared calendar. The Microsoft Graph model explicitly supports reading and writing events in shared or delegated calendars and is the supported way to automate this scenario.
4. If events are disappearing or being removed when manipulating shared calendars, review any removal of shared calendars or changes to sharing, as documented issues show that removing a shared calendar can delete events on the owner’s calendar.

Because the context does not provide a specific fix for CSV-imported events not propagating to other users’ shared calendars, the safest recommendation is to change the method of populating those calendars (direct creation, invitations, or a supported API-based solution) rather than relying on CSV import into a shared calendar.

References:

• Share an Outlook calendar as view-only with others
• Get shared or delegated Outlook calendar and its events
• If a shared calendar is removed, events may get deleted on the owner's calendar