Advanced Thermal Conversion (ATC) technologies, such as pyrolysis, gasification, and hydrothermal processes, are gaining attention as alternatives to land application, particularly as landbank constraints tighten and emerging risks such as PFAS come into focus. While these technologies are well established internationally, their application to sewage sludge in the UK presents a distinct regulatory challenge. Drawing on AtkinsRéalis’ project experience across multiple jurisdictions, this presentation focuses on how regulatory frameworks are being interpreted and applied to both sludge treatment through ATC and the use of resulting outputs. These classification questions have practical implications for environmental permitting, influencing plant design, operational requirements, and delivery timelines. At the same time, attention is increasingly turning to the regulation of outputs from ATC processes. This includes not only End-of-Waste considerations, but also the potential development of broader resource recovery frameworks and regulatory approaches that reflect a wider range of materials entering the market rather than traditional biosolids pathways alone. Positioned within the broader shift toward sustainable bioresource systems, this presentation shares insights from direct project experience and insights into international precedent, and highlights opportunities to further evolve regulatory approaches - supporting innovation while continuing to uphold high environmental standards.