This chapter addresses the paradigm shift from traditional financial accounting to integrated reporting incorporating environmental, social, and governance (ESG) dimensions. In continuity with prior chapters, it focuses on how regulatory developments, particularly the EU’s Corporate Sustainability Reporting Directive (CSRD) and European Sustainability Reporting Standards (ESRS), are transforming accounting practices, especially for SMEs. The chapter is structured into three sections. The first traces the historical evolution of accounting standards, highlighting the growing importance of extra-financial information. It emphasizes the increasing influence of stakeholders and neo-institutional theories in expanding corporate responsibility frameworks. The second section explores methodological approaches to integrated accounting. It presents the CARE method, which tackles green accounting by treating natural and human capital as depreciable assets, and the SEMA approach, a participatory framework tailored for SMEs that prioritizes materiality and stakeholder engagement. Both methodologies address the inadequacy of traditional accounting systems in capturing sustainability-related impacts, offering proportionate and actionable solutions. The third section presents a detailed case study: BON SPOT. This SME illustrates practical pathways for integrating ESG into business strategy, operations, and product innovation. Their experiences underscore key challenges—resource constraints, data complexity, and evolving standards—while demonstrating that phased, pragmatic sustainability implementation can yield competitive and relational advantages. This chapter ultimately argues that integrating extra-financial reporting into SME accounting is not merely a regulatory obligation but a strategic opportunity to reshape value creation in the sustainability era.