There is no single organization export, so the history comes out in parts. For work items, open or create a query, select the actions icon, then Export to CSV, which needs Project Administrators membership or View project-level information set to Allow and returns only the columns the query includes. For organization activity, go to Organization settings then Auditing then Download and choose CSV or JSON; this needs Project Collection Administrators or the View audit log permission, works only on organizations backed by Microsoft Entra ID, and covers at most the last 90 days.
What it holds
Git repositories, work items, boards and queries, pipeline runs, test plans, package feeds, and organization audit events.
Find the size
Organization settings then Storage under Artifacts shows total storage in GiB, but it covers package feeds only. For work items, use the row count a query returns before Export to CSV.
What to enter on the form
Azure DevOps in records, and the year your company started using it. Seller form