How to list all shared calendars in Microsoft Graph

Question

How to list all shared calendars in Microsoft Graph

Marcelo Amarante Cintra 0

I’m working on a feature in my product that needs to identify all calendars that have been shared with the signed-in user.

I would like to know whether Microsoft Graph provides a way to:

list every calendar that has been shared with the user, or
retrieve a list of users who have shared their calendars with that user.

Here is the issue I’m seeing:

The user has seven calendars shared with them, all with “Can Edit” permission. However, when I call the /me/calendars endpoint, only four of those seven shared calendars are returned.

Because of this, I’m unsure whether:

/me/calendars is expected to return all shared calendars,
some types of shared calendars are excluded from that endpoint,
there is another Microsoft Graph endpoint that should be used to retrieve the complete list, or
additional permissions / consent are required.

Could you please clarify the expected behavior and recommend the correct way to retrieve all calendars shared with a user?

Thank you

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Answer 1

Teddie-D 19,760 Microsoft External Staff Moderator

Hi @Marcelo Amarante Cintra

From my findings, there does not appear to be a dedicated endpoint that directly returns all calendars shared with the signed-in user or a separate list of users who have shared calendars with that user.

GET /me/calendars is the primary Microsoft Graph endpoint for retrieving the calendars available to the signed-in user. Microsoft documentation specifically states that it returns the collection of calendars the user has access to, including shared calendars that exist as local copies in the recipient's mailbox.

Microsoft Graph doesn't currently provide a dedicated endpoint that returns a list of users who have shared calendars with the signed-in user. Applications typically enumerate calendars from GET /me/calendars and inspect properties such as owner to determine whether a calendar belongs to another user.

If you're consistently seeing only four of seven shared calendars returned by GET /me/calendars, while all seven are visible in Outlook, that behavior appears inconsistent with the example in the documentation.

To help narrow this down, could you provide a bit more information?

Are the missing calendars shared from users in the same Microsoft 365 tenant, or from external organizations?
How were the calendars added (for example, via a sharing invitation, delegate access, or Outlook's Add calendar > From directory option)?
Do the missing calendars appear in both Outlook on the web and Outlook desktop?
Which Microsoft Graph permissions is your application currently using (for example, Calendars.Read, Calendars.Read.Shared, or Calendars.ReadWrite)?
Are the missing calendars user calendars, delegated calendars, shared mailbox calendars, resource calendars, or Microsoft 365 group calendars?

Please know that while our initial response might not resolve the issue right away, your input is incredibly valuable. With a bit more detail, we’ll work together to find the best solution for you.

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Marcelo Amarante Cintra 0 Reputation points

2026-07-22T12:47:42.28+00:00
Hello, @Teddie-D

Providing more information about the shared calendars:

The missing calendars are from the same Microsoft 365 Tenant.

The calendars where all shared via outlook invitation.

The missing calendars appear in both Outlook desktop and web.

Currently the application uses every possible calendar scope (Calendars.Read, Calendars.Read.Shared, Calendars.ReadWrite and so on), and it used to work the same way with only Calendars.Read.

Both the missing and the visible calendars are user calendars.

You shared the information that me/calendars should return every calendar that the user has access to, "including shared calendars that exist as local copies in the recipient's mailbox". How do I know if a shared calendar exists as a local copie in my mailbox? Is there a different way to share a calendar that creates a local copie in the recipient's mailbox?
Marcelo Amarante Cintra 0 Reputation points

2026-07-22T12:48:47.0866667+00:00

Something that I've tried and kind of worked: I accepted three invites to share a calendar in Outlook mobile, and it worked for one single user.

Anyway, this is a very inconsistent behavior that should be fixed and documented.
Teddie-D 19,760 Reputation points Microsoft External Staff Moderator

2026-07-24T02:19:02.14+00:00

Hi @Marcelo Amarante Cintra

Thank you for the additional information and for sharing the results of your testing.

Please note that we're not Microsoft Support, this is a user-to-user community forum. Forum moderators and contributors do not have access to your tenant environment or Microsoft's internal systems, so our guidance is limited to publicly available documentation and community experience.

A "local copy" is an Exchange Online implementation detail. When a shared calendar is added using the modern shared calendar experience, Exchange may create a synchronized calendar folder in the recipient's mailbox. Microsoft Graph can enumerate these calendars through GET /me/calendars. However, Graph does not expose any property or endpoint that indicates whether a shared calendar has been materialized as a local copy, nor does it document the conditions under which Exchange creates one.

Based on your testing, the missing calendars may not have been materialized as local copies in the recipient's mailbox, or that the synchronization state is inconsistent. Unfortunately, there is no supported Microsoft Graph API to verify or force this state, and the documentation does not describe why calendars with seemingly identical sharing configurations might behave differently.

If you're able to reproduce the issue consistently, we recommend opening a Microsoft Support ticket. The Exchange Online support team has access to mailbox-level diagnostics and backend service data that can help investigate synchronization status and identify any underlying service issues.

If you have an active Microsoft 365 subscription and hold the Global Admin role, you can submit a support request directly through the Microsoft 365 admin center. Otherwise, please contact your IT administrator to raise a support ticket on your behalf.

You can read more at: Get support - Microsoft 365 admin | Microsoft Learn