Purpose The purpose of this paper is to investigate how vulnerable consumers can be involved in transformative service design and how this approach may enhance the design of such services. The study also analyzes how co-design with vulnerable consumers differs from existing user involvement processes with the purpose of developing a co-design framework.

Design/methodology/approach A case study approach was employed, with six high schools in Australia identified as sites to conduct co-design sessions for a school-based alcohol education program. Adolescents were invited to review and (re)design an existing alcohol education program.

Findings The study indicates that co-design with vulnerable consumers cannot be approached in the same way as conventional user involvement processes. Based on the insights generated from six co-design sessions as well as the examination of user involvement and co-design literature, the authors propose a six-step co-design framework. The six steps comprise resourcing, planning, recruiting, sensitizing, facilitation and evaluation.

Research limitations/implications The co-design framework illustrates important differences to conventional user involvement processes. However, the generalizability of the research findings is limited to a specific study setting and a narrowly defined sample. Future research in a different setting is needed to further validate the presented findings.

Practical implications For service design practice, this study provides guidelines on how co-design activities with vulnerable consumers can be effectively resourced, planned, recruited, sensitized, facilitated and evaluated. The framework outlines how co-design may be applied so that vulnerable consumers can become empowered participants during the design process.

Originality/value This research contributes to the knowledge in transformative service research – a priority in service research – and service design by extending the boundaries of our understanding of processes and tools for the involvement of vulnerable consumers in transformative service design.