Share Calendars With Clients and Staff: Microsoft 365 and Google

Free/busy vs full details: the sharing levels

Every calendar share comes down to what the other person sees. The labels differ between Microsoft and Google, but the levels are similar.

For anyone outside the company, free/busy is nearly always enough. If a client needs to book time with you, a booking page is often better than a shared calendar; see our Calendly vs Cal.com vs Microsoft Bookings guide.

Microsoft 365: set the external calendar sharing policy

Microsoft's external calendar sharing page (updated March 2026) explains the admin switch. Without it, users can't share their calendars outside the organisation.

1. 1

   Open Org settings

   In the Microsoft 365 admin centre, go to Settings, Org Settings, Services tab, then Calendar.

2. 2

   Allow sharing with other Microsoft 365 users

   Tick "Let your users share their calendars with people outside of your organization who have Office 365 or Exchange". This covers clients who also use Microsoft 365.

3. 3

   Decide on anonymous sharing

   "Allow anyone to access calendars with an email invitation" lets people without Microsoft 365 view the calendar through a link. Turn it on only if staff need it.

4. 4

   Pick the maximum detail

   If anonymous sharing is on, choose free/busy with time only, time with subject and location, or all appointment information. Choose time only unless there is a clear reason.

5. 5

   Tell staff how to share

   Users share from Outlook on the web or Outlook desktop, choosing who and at what level. They can stop sharing at any time.

Google Workspace: set external sharing options

Google's calendar sharing settings page explains the admin limits. In the Admin console, go to Apps, Google Workspace, Calendar, Sharing settings.

• External sharing options for primary calendars: choose "Only free/busy information (hide event details)" for most businesses.
• Other options allow outsiders to see all details, change events, or even manage sharing. Avoid these for primary calendars.
• Internal sharing options: set what colleagues see by default. Many small firms allow full details internally.
• You can apply different settings to an organisational unit or group, for example stricter limits for HR or management.

Google says that once you limit external sharing, users can't exceed it, even when sharing individual events. It also notes that lowering the level may remove access people outside the company already had. And it points out that super admins, and admins with the Manage Calendars privilege, can see all event details in everyone's calendars, however calendars are shared.

Keep event titles private

Even with sensible limits, event titles leak information through forwarded invites, shared calendars and meeting rooms. A few habits keep sensitive meetings private.

Private events show as busy to people with view access, but delegates with edit rights may still see them depending on settings. Tell staff which colleagues have delegate access.

Room and equipment calendars

A meeting room booked through someone's personal calendar always ends in double-booking. Both platforms have resource calendars built for this.

Microsoft's resource mailbox guide says that by default anyone can book a resource and bookings are accepted automatically if it is free. Google's resource guide covers rooms, equipment and even company cars. For shared inboxes rather than calendars, see our shared mailbox vs group guide.

Sharing between a Microsoft 365 company and a Google client

Cross-platform sharing works, with limits. A Microsoft 365 user can share with a Gmail or Google Workspace user only through the anonymous link option, if the admin has enabled it. A Google Workspace user can share free/busy with a Microsoft user as an external person, within the admin's limit.

In practice, for ongoing work with one client, a booking page or a shared project calendar is cleaner than personal calendar sharing. If you are choosing a platform, our Microsoft 365 vs Google Workspace guide compares calendar and email features.

Do it yourself or get help?

Setting the admin limit takes five minutes in either console and is worth doing today. Help is useful when you are cleaning up years of ad-hoc sharing, setting up several rooms with approval rules, or moving between Microsoft 365 and Google.

Our Business Email Setup (S$249) configures Microsoft 365 or Google Workspace properly from the start, including calendar sharing limits and room calendars.