Sustainability-Linked Disclosure Quality, ESG Transparency, and Sustainable Finance Governance in the Indonesian Banking Sector

Sustainability-linked loans (SLLs) are performance-based financing instruments that link loan characteristics to borrowers' achievement of predefined sustainability performance targets. This study examines SLL disclosure quality, ESG transparency, and sustainable finance governance in the Indonesian banking sector. Using qualitative content analysis and a structured disclosure quality index, the study analyzes 2024 annual reports and official publications of Bank Mandiri, Bank Central Asia, and Bank SMBC Indonesia. The findings show that all three banks have incorporated SLLs or SLL-related instruments into sustainable finance narratives, but their disclosures remain largely aggregated and narrative. Bank SMBC Indonesia provides the clearest conceptual positioning by linking SLLs to transition financing, Bank Mandiri connects SLLs to broader sustainable financing priorities, and Bank BCA reports sustainable finance more conservatively without presenting SLLs as a stand-alone instrument. The disclosure quality index scores show Bank SMBC Indonesia (6/16), Bank Mandiri (5/16), and Bank BCA (3/16), indicating low SLL-specific transparency across all three banks. Quantitative KPIs, baselines, SPT calibration, margin adjustment mechanisms, and external verification remain insufficiently disclosed. Therefore, ROA, ROE, and NIM are treated only as contextual indicators, not as evidence of SLL financial effects. The study contributes by reframing early SLL adoption in Indonesia as a governance and disclosure quality issue rather than as a direct profitability question.