ISO 42001 vs ISO 27001: what actually differs
18 June 2026 · 6 min read · Certification
Both are management system standards with the same skeleton. The difference is what you are managing, and the evidence an auditor expects.
Same skeleton, different subject
ISO 42001 follows the same Annex SL structure as ISO 27001: context, leadership, planning, support, operation, evaluation, improvement. If you already run an ISMS, the clause structure will feel familiar and much of your governance machinery transfers directly.
What changes is the object of management. ISO 27001 manages risk to information. ISO 42001 manages risk arising from AI systems, including risk to people affected by them, which is a genuinely different lens for most security teams.
The impact assessment is the new muscle
The single biggest addition is the AI system impact assessment. It asks you to consider consequences for individuals and groups, not only for the organisation. Security teams accustomed to CIA triad thinking usually need to widen their methodology rather than reuse it unchanged.
Auditors will look for a repeatable method, completed assessments for real systems, and evidence that findings changed something.
Run them together if you can
Where both standards are in scope, an integrated management system avoids duplicate policies, duplicate internal audits, and duplicate evidence collection. Shared clauses are documented once; the AI-specific controls sit alongside the Annex A control set rather than in a separate silo.
The practical saving is largest in clauses 4 through 10, which can be almost entirely common.
Working through this yourself?
We run ISO 27001 and ISO 42001 readiness programmes and quantum training for teams facing exactly these decisions.
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