This research paper explores the critical success factors for a contract with budgetary control service providers in facility management. Today, for most contracts in Europe (especially in Switzerland), the client side is responsible for the budget and the spending decision. Commonly the provider is not motivated to achieve savings for the client, since the provider would earn less. The paper focuses on the reasons for a contract with budgetary control for the client, as well as for the provider, along with how the relationship between the two parties is influenced. The background theory provides information on contracts in FM and incentive systems. These elements form the guiding structure for the empirical research, based on a qualitative case study approach. Semi structured interviews were conducted to gain information of the practise. This information is compared to the background theory and discussed to deliver tangible results for client and provider. The results gained state reasons to handover budgetary control to the provider as security in planning and keeping to the budget. Furthermore it can be said, that a main part for a successful contract with budgetary control are the tender documents provided by the client, including definitions and strategies along with knowledge of the building(s).