Blockchain technologies are based on a distributed and transaction oriented concept. This is why experts not only consider Blockchain technologies to be the foundation for digital currencies but also to have potential to significantly shape our society in many different ways. Business innovations, in particular, can be driven by the integration of Blockchain into already existing system landscapes. For example, combining Blockchain technologies with enterprise resource planning systems leverages opportunities for new or optimized business processes in the supply chain. Especially the integration of Blockchain into the procure-to-pay process makes a so-called cross-company single source of truth in a supplier network possible. Therefore, Blockchain enables to build greater trust between the business partners and to increase the speed, transparency and the cost efficiency of processes. However, current research in this field is only at its beginning. There is still a lack of research and experience with the integration of Blockchain technologies into existing business landscapes. Many challenges still have to be tackled and more experience needs to be gained in order to ensure a productive use of Blockchain in the procure-to-pay process. Therefore, the requirements and challenges regarding the integration of Blockchain into ERP systems based on the example of the procure-to-pay process from the car manufacturer Daimler were identified in the frame of this research paper. For this purpose, interviews with experts from Daimler were conducted. The resulting conceptual architecture model is presented along with a proof-of-concept based on a software prototype.