Hi @Glenn Maxwell ,
As per as my research, when a user creates a Bookings calendar a scheduling mailbox is created.
You can use Get-Mailbox -RecipientTypeDetails SchedulingMailbox cmdlet to list the scheduling mailboxes and confirm if it is a booking mailbox, more details please refer to: https://techcommunity.microsoft.com/t5/microsoft-bookings-blog/microsoft-bookings-behind-the-scenes/ba-p/2887256
Yes, you can use remove-mailbox cmdlets to delete booking page mailbox, as well as Delete user action in M365 admin center.
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