Audit, assurance & evidence · Core
Reasonable assurance
Also called: high assurance, high-level ESG assurance
ELI5
A high but not absolute level of assurance supported by sufficient evidence.
Used in conversation
“The assurance team asked for the evidence supporting reasonable assurance.”
Pitch context
You will see “Reasonable assurance” in board papers, contracts, policies, risk registers and compliance reports when the discussion reaches audit, assurance & evidence.
Why it matters: In audit, assurance & evidence, a loose definition can change rights, obligations, approval, disclosure or enforceability.
Caution
Meaning, enforceability and required process vary by jurisdiction and agreement; this definition is not legal advice.
Connected terms
- Limited assuranceLimited assurance uses less extensive procedures and a negative-form conclusion; reasonable assurance provides a higher, though not absolute, level.
Sources & evidence · 9
Direct term-level sources and supporting source families.
- IFRS Foundation — IFRS GlossaryDirect source · primary · checked 2026-08-16
- Financial Accounting Standards Board — FASB Accounting Standards CodificationDirect source · primary · checked 2026-08-16
- OECD — G20/OECD Principles of Corporate Governance 2023Direct source · institutional · checked 2026-08-16
- IFRS Foundation / International Sustainability Standards Board — IFRS S1 and IFRS S2 Sustainability Disclosure StandardsDirect source · primary · checked 2026-08-16
- GHG Protocol — Standards and GuidanceDirect source · institutional · checked 2026-08-16
- International Organization for Standardization — ISO Net Zero Guidelines and related workDirect source · institutional · checked 2026-08-16
- U.S. Federal Trade Commission — Advertising and Marketing GuidanceDirect source · primary · checked 2026-08-16
- U.S. Securities and Exchange Commission — EDGAR and filing resourcesSupporting source family · primary · checked 2026-08-16
- National Institute of Standards and Technology — Computer Security Resource Center GlossarySupporting source family · primary · checked 2026-08-16