Purpose: Many countries aim to improve public services by use of information and communication technology (ICT) in public service supply chains. However, the literature does not address how inter-organizational ICT is used in redesigning these particular supply chains. The purpose of this paper is to explore this important and under-investigated area. Design/methodology/approach: An explorative multiple-case study was performed based on 36 interviews, 39 documents, extensive field visits and observations providing data on digital transformation in four European criminal justice supply chains. Findings: Two different design approaches to digital transformation were found, which are labelled digitization and digitalization. These approaches are characterized by differences in public service strategies, performance aims, and how specific public characteristics and procedures are dealt with. Despite featuring different roles for ICT, both types show the viable digital transformation of public service supply chains. Additionally, the application of inter-organizational ICT is found not to automatically result in changes in the coordination and management of the chain, in contrast to common assumptions. Originality/value: This paper is one of the first to adopt an inter-organizational perspective on the use of ICT in public service supply chains. The findings have scientific and managerial value because fine-grained insights are provided into how public service supply chains can use ICT in an inter-organizational setting. The study shows the dilemmas faced by and possible options for public organizations when designing digital service delivery.