What is a service delivered between two business units in the same organization known as?

Strategic service is not a defined ITIL classification used to describe services delivered between internal business units.

Delivered service is not a recognized ITIL term for categorizing the relationship between business units within an organization.

ITIL defines an internal service as one delivered by an IT service provider to the same organization - that is, between departments or business units within a single enterprise. This classification aligns with the Type I (internal) and Type II (shared services) service provider models. It contrasts directly with an external service, which is delivered to customers or parties outside the provider's own organization.

An external service is specifically one delivered to customers or organizations outside the service provider's own enterprise, not between internal business units.