The Applied Behavioural Science Start Up Pack is a practical resource designed to help teams integrate a behavioural science lens into technology and innovation projects in low-resource settings. Developed through research and collaboration with the FCDO Technology and Innovation Unit, partners and grantees, the pack brings together two complementary resources: the Triage Tool, which helps teams decide early on whether and where a behavioural lens is needed, and the Field Guide, which provides step-by-step guidance on how to apply it in practice. Supported by AI augmentation guidance and intended for a wide range of users, this pack is designed as a flexible, adaptable starting point to strengthen decision-making, enhance project design, and ultimately improve outcomes.