The objective of this paper is to define key success factors for implementing joint services in the public sector. The concept of joint services appeared first in the private sector. It is mainly defined as the concentration or consolidation of functions, activities, services or resources into one stand-alone unit as a provider for the client units. The joint service model is described as being akin to an open market system, in which the provider and client units are in partnership in a similar way a company enters into an agreement with its customers. We have identified key success factors for implementing shared service centers in local government units. The results are based on literature studies and empirical research.