What Do We Know About Scope 3 Emissions in Small‐ and Medium‐Sized Enterprises? Mapping Current Knowledge and Advancing a Theory–Practice‐Oriented Framework

Although SMEs comprise over 90% of firms globally, research on their engagement with Scope 3 (value‐chain) greenhouse gas emissions remains limited. This PRISMA‐guided systematic review synthesises 49 SME‐relevant studies to develop a theory‐informed, practice‐oriented framework for more credible and sustained Scope 3 engagement. The review identifies a pronounced large‐firm bias and shows that SME Scope 3 engagement is driven largely by cascading buyer and regulatory pressures operating through asymmetric supply‐chain relationships. Engagement is constrained by limited activity data, methodological fragmentation, weak internal capabilities and low digital readiness. Integrating institutional, stakeholder, power‐dependence and capability perspectives, we advance a governance–capability framework linking external pressures with supply‐chain collaboration and capability development to support iterative learning, improved data quality and continuous improvement. The study demonstrates how strategic governance and capability development can move SMEs beyond symbolic compliance towards substantive, sustained Scope 3 management and value‐chain decarbonisation. It offers actionable guidance for buyers, policymakers and intermediaries designing SME‐friendly Scope 3 support programmes.