Internal services
From ControllingWiki
IGC-DEFINITION (abbreviated)
Internal services / Innerbetriebliche Leistungen
Internal services are what one cost center provides for another. If the exchange of services can be measured and if the amount of service procured is dependent on the actual activity of the center procuring the service, then the internal services are calculated according to work reports. But if the exchange of services cannot be measured clearly, then the costs are apportioned according to a pre-established key (allocation of costs) or a service level agreement is drawn up to charge the costs. Internal service calculations are always carried out with planned cost rates, which result from annual budgeting.
from: IGC-Controller-Wörterbuch, International Group of Controlling (Hrsg.)
Wow, this is in every rescpet what I needed to know.