Business-to-business customer loyalty management is an essential and long-standing theme in business research and practice. Loyal clients are of great importance within Software-as-a-Service (SaaS), as the business model relies strongly on long-term business relationships, e.g. due to subscription models. Nevertheless, to the best of our knowledge, there is no study on how to design loyalty initiatives used in business-to-business SaaS relationships yet. Therefore, our thesis asks the question “How can loyalty initiatives be designed to improve the loyalty of SaaS business clients?”. By applying a qualitative research methodology with multi-case studies, we were able to investigate the status-quo of customer loyalty management by looking at the vendor side and then analysing the perception of loyalty initiatives, with respect to the client’s perspective. A broad number of in-depth empirical data was collected in semi-structured interviews conducted with employees of six SaaS vendor firms and seven of their clients. As we used an abductive approach, we were able to compare our findings with the existing literature and extend previous theory. Our interview findings were then clustered into eight dimensions, which were based on the customer lifecycle, and various initiatives have been assigned to them. All initiatives included several actions performed by the vendors, which were then classified into three categories, according to how important it was perceived by their clients. We concluded our research with the ‘Design Guide for Loyalty Initiatives’ that summarises our findings and provides an overview for SaaS vendors to review and adjust their initiatives. Hence, we deliver valuable insights for SaaS vendors to gain a deeper understanding of their clients’ needs and to, in turn, prioritise their performed loyalty actions and allocate their budget accordingly.