Information systems are used for managing and supporting companies’ business relationships and have become an important part of companies’ exchanges with their customers. Information systems are usually managed by a third party, an information system provider (IS-provider). Companies are dependent on their information systems to maintain their business performances and are therefore also dependent on the IS-provider's competence. This paper studies the impact that a company’s IS-provider relationships have on its customer business relationships. By using the concept of connection and studying its degree of continuity and strength, the study offers insight on the impact of the IS-providers' relationships on a company's customer relationships. The study consists of a case study involving five customer relationships and four IS-provider relationships, creating twenty within-cases. The result shows that the companies' relationships are dependent on the exchanges with the IS-providers. This impact and the characteristic of the connection may vary over time, making the concept of continuity important to consider when evaluating a company's relationship with IS-providers. The study shows that it is important for companies to consider these two business relationships in relation to one another when managing the IS-provider relationship and the information systems that are used in customer relationships. Important management aspects can be missed in the evaluation of an IS-provider, if the connection between the relationships is left out of the analysis.