I haven't seen this as a suggestion yet: Predictive Billing for Atlassian Cloud.
Org Admins create Jira and Confluence instances that grow in user counts. How can we predict this growth?
One way is to have a booking system setup for the administrators of each instance. They land on a JSM portal, and based on their user count growth (perhaps a graph and notification), they can request more licenses by a certain date. They make this booking for license growth, and this allows everyone to adapt with the corresponding SLAs setup.
This could be set to a calendar on the Agent interface.
Likewise, if a large amount of users has to be added by a certain date, this too could be booked ahead of time.
This future billing could be automatically summarized for the entire Cloud instance, and categorized, along with a difference in costs between now and a certain date.