Public procurement is widely used in order to incorporate competition into public services. Competition in procurement often leads to efficiency but the process can also raise some problems. While providing the procurement documents you do not know who will be your upcoming partner. Another aspect is how flexibility can be managed in contract design while maintaining a high service quality. The aim of this study is twofold. Firstly, the aim is to investigate how flexibility has been expressed and historically described in bus tendering documents. Secondly, to explore how the actors define or describe flexibility and its importance in tendering. Data was collected from ten years of tendering documents in the bus sector in Sweden and from interviews and a workshop. The results showed that flexibility in tendering documents has been and still is low for the operators. However, the actors wish for more flexibility and new forms of contracts can make it easier to include higher degrees of flexibility in future contracts. The paper contributes to the ongoing discussion about how to design contracts and to manage flexibility. The study has potential to create knowledge and contribute to better decision making for future procurement of bus transport.