Governance Briefing — IAASB ISSA 5000 sustainability assurance standard

Executive briefing: The International Auditing and Assurance Standards Board issued International Standard on Sustainability Assurance (ISSA) 5000 in December 2023. The standard is effective for assurance engagements on sustainability information for periods beginning on or after 15 December 2026. Boards and audit committees must ensure governance over sustainability reporting controls, evidence, and assurance coordination aligns with ISSA 5000 requirements.

Key governance signals

Assurance readiness. ISSA 5000 requires management to establish robust processes and controls for preparing sustainability information subject to assurance.
Audit committee oversight. Audit committees must oversee assurance scope, independence, and findings, integrating them with financial reporting oversight.
Reporting quality. Entities must provide complete, accurate, and supportable disclosures to enable assurance providers to obtain sufficient appropriate evidence.

Action checklist

Perform gap assessments comparing current sustainability reporting controls with ISSA 5000 expectations.
Coordinate audit committee agendas to cover sustainability assurance planning, provider selection, and remediation follow-up.
Integrate sustainability data governance into internal control and SOX-equivalent frameworks.

Enablement moves

Develop documentation standards capturing data lineage, estimation methodologies, and management review procedures.
Engage assurance providers early to define scope, criteria, and readiness milestones.
Train finance, sustainability, and internal audit teams on ISSA 5000 requirements and evidence expectations.

Sources

Zeph Tech equips audit committees with ISSA 5000 playbooks covering governance, evidence, and assurance provider coordination ahead of the 2026 effective date.