Outlook calendar sharing levels: busy only, titles and locations, or all details
Outlook offers several sharing levels, and the difference between the first three is exactly the information a colleague learns about each appointment. Removing someone does not always take them to zero, because of an organisation-wide default. Arte Soft, the developer of Cloud Calendars, wrote this guide to Microsoft 365’s own sharing controls.
What each level reveals
| Level | Busy times | Title and location | Notes and other details | Can change items | Outside organisation? |
|---|---|---|---|---|---|
| Can view when I’m busy | Yes | No | No | No | Yes, if allowed by the organisation |
| Can view titles and locations | Yes | Yes | No | No | Yes, if allowed by the organisation |
| Can view all details | Yes | Yes | Yes | No | Yes, if allowed by the organisation |
| Can edit | Yes | Yes | Yes | Yes | No |
| Delegate | Yes | Yes | Yes, plus private items if allowed | Yes, and handles meetings | No |
What most people assume
Removing a colleague from my sharing list means they can no longer see anything on my calendar.
The levels, in Microsoft’s words
Microsoft lists: Can view when I’m busy (availability without details such as location), Can view titles and locations (availability plus titles and locations), Can view all details, Can edit, and Delegate. Can edit and Delegate are only available when sharing with people in your organisation.
Microsoft also says calendar items marked Private are protected: most people you share with see only the time of a private item, not its title or location, while delegates can be allowed to see details.
Worked example: one entry, three viewers
A fictional account manager has a non-private entry, “Pricing review — Contoso — Room 3B, 14:00–15:00”. A colleague with Can view when I’m busy sees the busy interval. Can view titles and locations reveals the title and room but not the appointment’s other fields. Can view all details reveals the calendar event’s available details; it does not establish permission to open a separately protected linked document or file.
If the manager marks the entry Private, all three see only that 14:00–15:00 is taken. Choose the lowest level that lets each person do their job: scheduling around you needs only the first.
The My organization default
Outlook may list a “My organization” entry in sharing. Microsoft describes it as the default level colleagues get, for example when they use the Scheduling Assistant. When you remove a named person, Microsoft says that if My organization is set to anything other than None, that person’s view updates to the default level rather than disappearing.
So a colleague you remove from Can view all details may still see titles and locations if that is your organisation default. Check the My organization row after every removal.
Change, remove and confirm
In Outlook on the web, right-click the calendar name, choose Sharing and permissions, then select a new level or remove the person. Microsoft notes that calendar sharing may be unavailable for your account or limited to your organisation, depending on organisation settings.
Microsoft’s newer sharing model displays simplified permission levels. Intermediate levels can still be configured by an administrator using mailbox-folder permission commands and appear as Custom. Client interfaces may allow an attempted action that the service then rejects; the service evaluates the underlying rights. Ask the administrator what the effective grant allows rather than treating every Custom level as unsupported.
How recipients receive your calendar
In the newer Exchange Online model, a copy of the shared calendar is held in the recipient’s mailbox. Instant syncing is supported for specified configurations, including users within the same Microsoft 365 tenant, and supported Outlook, REST and Exchange ActiveSync applications. It is not universal for cross-tenant sharing. Microsoft says EWS does not support instant syncing; that is not a statement that EWS cannot access calendars at all. After an automatic upgrade, the copy includes the previous year and future events, including recurring series with relevant instances.
Microsoft also warns that some Exchange ActiveSync apps let a read-only recipient try to create or respond to a meeting on your calendar; the change saves locally and is then rejected by the server. A recipient who “edited” your calendar on a phone may simply be seeing a rejected local change.
What it looks like
Cloud Calendars overview, using our product images. Provider settings and protocol examples described in this guide are separate from the screens shown here.
What to do
- Decide what each colleague needs: availability, titles and places, or full details.
- Grant the lowest level that does that job.
- Mark sensitive entries Private; most viewers then see only the time.
- After removing anyone, check the My organization default.
- If a grant appears as Custom, ask the administrator what the actual permission permits; clients and the service may handle attempted actions differently.
Questions
- Can “Can view when I’m busy” reveal where I am?
- Microsoft describes it as showing availability without details such as location. Titles and locations require the next level.
- I removed someone but they still see my appointment titles. Why?
- Microsoft says removed people fall back to the My organization default if it is set above None. Lower or remove that default.
- A colleague with view access says they moved my meeting on their phone.
- Microsoft notes that some ActiveSync apps let read-only recipients make local changes that the server then rejects. Check your calendar in Outlook.