Loyalty systems are a very popular service employed by retailers in order to measure and reward customer loyalty. However, currently deployed systems introduce many privacy risks, as the users’ data is completely controlled by retailers. In this work we tackle this issue by investigating the requirements posed on a privacy-friendly loyalty system and proposing a new design for a digital loyalty system. With this novel approach, the users are given more control over their data, but retailers are still able to measure their loyalty and perform (authorised) data collection. Additionally, the functionality of the design is flexible and allows for deployment of more advanced services.