The COVID-19 pandemic highlights the dependence on digital public service delivery in many nations. The intensified use of digital public services also shifted the spotlight to accessibility and reactive design of digital public services. Inspired by the high level of proactivity provided in commercial digital services, policy-makers are looking for guidance on employing the vast amount of (personal) data available at various public agencies to proactively aid citizens during important life events. Proactivity, however, is a very complex multi-level concept with a myriad of case-specific forms and conditions and is not always desired. Moreover, there is little guidance in the literature on how to classify the level of proactivity and design more proactive public services. The objective of this paper is to provide guidance for classifying, understanding, and designing proactivity. Drawing on previous conceptualizations in literature, this paper introduces a proactivity classification framework that is substantiated using empirical cases from the Netherlands. We found that fully proactive services are not always desired or possible due to public service characteristics. The two key variables in this framework - service eligibility and service delivery - were used to propose design principles for increasing public services' proactivity. The principles were validated and prioritized by four public service innovators. Policy-makers looking to enhance inclusivity through service proactivity can start by classifying current services and integrating the design principles in their innovation roadmap.@en