Share your Microsoft 365 calendar with colleagues, or with clients and suppliers outside your business, so they can see when you're free or view your appointments. This guide covers the admin setting that allows external sharing, how users share from Outlook on the web, new Outlook and classic Outlook, publishing a calendar link, and how to stop sharing.
Which kind of sharing do you need?
| You want to | Use | Admin setting needed? |
|---|---|---|
| Let a colleague see or edit your calendar | Share with a person in your organisation | No, it works out of the box |
| Let someone at another business that uses Microsoft 365 see your availability or appointments | Share with an external person | Yes: external sharing |
| Let someone using Gmail, iCloud or anything else see your calendar | Share with an external person (they get a read-only link), or publish your calendar | Yes: external sharing plus anonymous access |
| Let an assistant manage your calendar and meeting requests | Delegate access | No. See Give someone access to your mailbox or calendar |
Permission levels explained
When you share, you choose how much the other person sees. The same names are used in all current Outlook apps:
| Permission | What they see or do | Available to |
|---|---|---|
| Can view when I'm busy | Only your free and busy blocks, with no titles or details | Colleagues and external people |
| Can view titles and locations | Free and busy time plus each event's subject and location | Colleagues and external people |
| Can view all details | Everything in your events except items you mark Private | Colleagues and external people |
| Can edit | View and change your events | Colleagues only |
| Delegate | Edit your calendar and receive and respond to meeting requests on your behalf | Colleagues only |
Step 1 (admin, once): allow sharing outside your business
Skip this if you only share with colleagues. You need to be a Global or Exchange administrator.
- Open the admin centre. Sign in at admin.microsoft.com.
- Go to Org settings. In the left menu choose Show all if needed, then Settings → Org settings.
- Open Calendar. On the Services tab, select Calendar.
- Turn on external sharing. Tick Let your users share their calendars with people outside of your organization who have Office 365 or Exchange.
- Allow non-Microsoft recipients (optional). To let users share with people on Gmail, iCloud and other services, also tick Allow anyone to access calendars with an email invitation. This option only appears once the first box is ticked.
- Choose the maximum detail. Pick what users are allowed to share externally: Show calendar free/busy information with time only, Show calendar free/busy information with time, subject, and location, or Show all calendar appointment information. Users can always share less than this, never more.
- Save. The change usually takes effect within an hour.
Step 2: share your calendar
Outlook on the web and the new Outlook for Windows
- Open Calendar from the app bar on the left.
- Select Share on the toolbar (in the new Outlook it's on the Home tab as Share calendar), then choose which calendar if you have more than one.
- Add the person. Type their name or email address and select them from the list.
- Pick a permission level from the drop-down next to their name.
- Select Share. They receive an email invitation to add your calendar.
Classic Outlook for Windows
- Open your calendar, then on the Home tab select Share Calendar and choose the calendar.
- Select Add in the Calendar Properties window and choose the person from the address book, or type an external email address.
- Choose the permission level under Permissions, then select OK.
Outlook for Mac, iPhone and Android can share calendars too. In the Outlook mobile app, open the calendar list, tap the settings icon next to your calendar and choose Add people.
What the other person needs to do
- Colleagues select Accept in the invitation email. Your calendar then appears under People's calendars (or Shared calendars) in every Outlook app they use, including their phone. They can also add it themselves: Add calendar → Add from directory in Outlook on the web, or Open Calendar → From Address Book in classic Outlook.
- External Microsoft 365 users accept the invitation in the same way and see your calendar alongside theirs.
- Gmail, iCloud and others get a link to a read-only internet calendar (ICS) that they can subscribe to. It updates on their provider's schedule, often every few hours rather than instantly.
Publish your calendar as a link
Publishing gives you an HTML link (viewable in any browser) and an ICS link (for subscribing in another calendar app). It's handy for a public availability page or a contractor who doesn't use Microsoft 365. It requires the anonymous option from Step 1.
- Open Settings (gear icon) in Outlook on the web or new Outlook, then Calendar → Shared calendars.
- Under Publish a calendar, choose the calendar and the level of detail, then select Publish.
- Copy the HTML or ICS link and send it to whoever needs it.
To stop a published link working, return to the same place and select Unpublish. Publishing again creates new links, so old copies stop working.
Stop sharing or change permissions
- Outlook on the web and new Outlook: right-click your calendar under My calendars → Sharing and permissions. Change the drop-down for a person, or select the remove (bin) icon.
- Classic Outlook: right-click the calendar → Properties → Permissions tab, select the person and choose Remove.
Troubleshooting
"Sharing isn't allowed with this person" or the external option is greyed out
External sharing hasn't been turned on in Step 1, or the detail level you picked is higher than your administrator allows. Wait up to an hour after the admin change, then try again.
The external person can only accept with a Microsoft account
That's expected when they use Gmail or another non-Microsoft service with the full-sharing invitation. Ask them to use the ICS link in the email to subscribe instead, or publish your calendar and send them the ICS link.
My colleague sees "Free" or "Busy" but no details
Everyone in your organisation can see your free and busy time by default, which is different from sharing. Share your calendar with them at Can view titles and locations or Can view all details, and check the events aren't marked Private.
Shared calendar doesn't update or shows an old copy
In classic Outlook, remove the shared calendar and add it again. If it was shared years ago, the old-style sharing can leave a stale copy. External ICS subscriptions refresh on the subscriber's schedule; Google Calendar can take up to a day.
Last reviewed: October 2026
