Forum Discussion
Microsoft Bookings double-booking staff despite busy calendar entries
Hello everyone,
We are experiencing an issue with Microsoft Bookings. Our setup allows external customers to book appointments via the published booking link on our website. However, we have noticed that staff members can still be double-booked, even when their Outlook calendars show them as “Busy.”
Here’s what we have already done to try to resolve the issue:
- Ensured that the option “Events on Office calendar affect availability” is enabled for all staff in Bookings.
- Verified that in Outlook, the staff calendars have appointments marked as “Busy” to reflect their availability.
- Shared staff calendars with the Bookings account and set default permissions to “When I’m busy” (we also changed “People in my organization” to “When I’m busy”).
- Checked that the booking page settings are set to respect staff availability.
Despite these steps, the system still allows bookings to be made during times when staff are busy.
Our staff mailboxes are hybrid (both on-premises and in Exchange Online), and we are running a hybrid setup in general.
We are wondering if anyone else has experienced this issue and if there are recommended solutions or workarounds.
Thank you for any insights!
1 Reply
This issue often happens in hybrid Exchange setups because Bookings can’t always read the “busy” status correctly from on-prem mailboxes, even if you’ve set everything up to respect availability. Bookings works best when the staff mailbox is fully in Exchange Online, so if you test with a cloud-only user you’ll likely see it behave properly. In a hybrid setup, free/busy sharing can be unreliable, which is why double bookings slip through. If moving mailboxes online isn’t possible right now, a common workaround is to use a cloud resource calendar for Bookings and then forward those events to the on-prem mailbox. That way, Bookings always sees the right availability, and your staff still get their appointments.
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