ABSTRACT This paper addresses the challenges facing managers of Small‐ and Medium‐Size Enterprises (SMEs) when conducting environmental sustainability assessment at the value chain level, particularly Scope 3 Greenhouse Gases (GHG) emissions. The paper investigates issues related to data availability and data quality for Scope 3 assessment and identifies dimensions of Scope 3 reliability. Utilising a series of in‐depth case study analyses with SMEs in the south‐west of England, UK, the paper fills a gap in supply chain sustainability research by identifying practical challenges. The findings show that SMEs encounter persistent difficulties in assessing emissions associated with purchased goods and services and downstream activities linked to the life cycle of products and services. Limited supplier data, reliance on estimation methods, boundary issues and risks of double‐counting all hinder accuracy. Despite these limitations, emissions ‘hotspots’ can still be identified to target improvement activities, suggesting that a qualitative assessment approach may be more practical for SMEs than precise carbon accounting. While previous literature emphasises comprehensive carbon accounting, this paper reveals the gaps between theoretical frameworks and real‐world constraints and practicalities. By examining the limitations of supplier data, estimation methods and double‐counting risks, this research provides a nuanced perspective on the feasibility of emissions measurement for SMEs and a practical way forward.
Halat et al. (2026) studied this question.