The Managed Zone Service closed in October 2021 and all data migrated to Mythic Beasts. Managers of domains were sent information about the process and how to regain management access, post the migration, by email during September 2021.
For new registrations, groups should register these themselves, through Mythic Beasts or a service of their choice. An exception is for domains attached to another service provided by the UIS (such as a website) - in this case, it may be more appropriate for the UIS to obtain the domain on behalf of the institution and manage it on their behalf, as they can make changes as required by technical changes (e.g. adjust a records if a website is moved).