This paper aims to examine how European sustainability reporting intersects with assurance practices in the social pillar, focusing on Diversity and Inclusion (D&I) disclosure within Italian Other Systemically Important Institutions (O-SIIs). It assesses the extent to which disclosed D&I key performance indicators (KPIs) are covered by assurance, and how disclosure and assurance vary across institutions and providers absent fully shared benchmarks.
This study adopts a two-phase qualitative content analysis grounded in signaling, governance and institutional theory and a decision-usefulness perspective. An original interpretive model, developed inductively around five dimensions (Governance and Strategy, Workforce Composition, Inclusive Practices, Access and Impact, Assurance and Verification) aligned with European Sustainability Reporting Standards (ESRS), is applied deductively to seven O-SII banks in Italy in 2025, whose 2024 reports coexist under the Corporate Sustainability Reporting Directive (CSRD) and Non-Financial Reporting Directive (NFRD) regimes within the same national context and reporting year.
All seven banks formalize D&I policies, targets and workforce and inclusion metrics, confirming D&I as a structural governance component. Yet none receives point-by-point assurance on individual D&I KPIs: all are limited to report-level assurance, regardless of regime or provider, revealing a persistent fracture between disclosure depth and verification depth.
Findings point to the need for shared benchmarks, standardized KPI definitions and clearer ESRS-based assurance perimeters, identifying ISSA 5000’s entry into application as a critical juncture for closing the D&I disclosure-verification gap.
This paper offers a dual contribution: an original interpretive model bridging D&I disclosure and assurance, and its first empirical application to O-SII banks straddling the CSRD/NFRD transition, showing assurance signaling weakens when engagement design converges at a common, minimum standard.
