Professional Judgment and AI Disclosure Governance in Audit and Sustainability Assurance: Public Evidence from the UK Big Four

Abstract

Artificial intelligence (AI) is entering audit workflows while sustainability reporting expands the evidence subject to professional evaluation. This exploratory study examines how the UK Big Four publicly describe safeguards that keep AI-assisted work human-led, reviewable and accountable. The complete 2024 transparency-report cross-section was coded against seven pre-specified dimensions and summarized in an AI–Judgment Governance Disclosure Index (AI-JGDI). The index measures AI disclosure governance—the completeness of public accountability commitments—not internal control effectiveness. Firm evidence is reported with page-level passages and a decision-level coding log; the single-coder design remains a substantive limitation. The results are compared only as external context with recent inspection outcomes published by the UK Financial Reporting Council. All four firms disclose deployed AI capabilities and retained human responsibility; disclosure is most complete for oversight, accountability and learning, and least complete for AI-specific validation and engagement-level traceability. Sensitivity analysis supports the broad cross-firm pattern but not a precise ranking. The audit evidence is empirical; the sustainability-assurance extension is analytical. Across the four reports, AI disclosure governance and sustainability-assurance disclosures remain largely parallel, with no explicit engagement-level methodological link identified.