The "Terminate domain at the registrar" option for the domain registrar plugins for Denic is needed. Especially, because .de domains registered with denic never expire. Also for Denic there could be another way to get rid of domains for a provider, called TRANSIT. This returns the domain to the Denic-Registry, which calls the domain owner for the future and the former provider is not longer responsible for the domain and will not be charged for it any more. This is a legal way to get rid of a domain which a customer not has allowed to delete.