This guide is designed to help anyone in the health and immunization system identify and address barriers or leverage drivers to immunization by locally codesigning and evaluating human-centred, tailored immunization programmes. In four stages - Diagnose, Design, Implement and Evaluate - this guide outlines a cyclic process to overcome hurdles to vaccination. This guide can be used to tailor programmes for any priority group or vaccine across the life course. The strength of the process is in the engagement of stakeholders, particularly end-users at each stage. It supports local ownership, transparency, and accountability, and enhances programmes’ ability to listen and learn to better understand community perspectives. This guide leverages UNICEF’s Human Centred Design 4 Health (HCD) and WHO’s Tailoring Immunization Programmes (TIP) to create a consolidated and simplified strategy for evidence-based co-design suited to low-resource settings: HCD-TIP.