[updated 27.06.2024]
Rhino 8 users who have purchased and registered a license also have access to Rhino 7 (for Windows and macOS) and thus to Rhino 6 and, for a limited time, to Rhino 5. This also applies to upgrade license, not just full licenses as it was before.
After adding the license to Rhino Accountor after validating the license on a specific computer, the older version key can be obtained from the following page (by enetring the same email as in Rhino Account or used for validation):