The aim of this study is to structurally explain the role of sustainable financing in shaping the sustainability reporting of the Iranian banking industry and to provide a local framework for its measurement and disclosure. The research was conducted with a mixed approach and sequential exploratory design. In the qualitative phase, data were collected through 14 semi-structured interviews with banking, risk management, and financial reporting experts and analyzed with a systematic approach of data-based theory. Then, using interpretive-matrix analysis, the relationships and levels of influence of the components were determined. To strengthen external validity, a case study analysis of published reports of Iranian banks was also conducted. The findings show that credit portfolio orientation, systematic integration of environmental and social risks in risk management, and quantitative disclosure requirements are the driving dimensions in bank sustainability reporting. Accordingly, a set of operational indicators for measuring sustainable finance was presented and a local, multi-level framework was developed to link credit policies, non-financial risk management, and disclosure structure. The results indicate that without quantitative measurability and alignment of credit allocation with sustainability objectives, reporting remains limited to the level of descriptive disclosures. The proposed framework can be a basis for national standardization of sustainability reporting and strengthening supervision in the banking system.