NIS2 Documentary Evidence and Audit Readiness: How to Structure Compliance Proof


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NIS2 Documentary Evidence and Audit Readiness: How to Structure Compliance Proof

February 14, 2026

The ACN baseline guidance emphasizes documentary evidence as a core compliance requirement, not a post-hoc activity. For governance and GRC teams, audit readiness depends on maintaining coherent evidence sets across policies, inventories, plans, and operational records linked to baseline obligations.

Sources: ACN baseline reading guide, ACN baseline obligations determination

Key takeaways

  • Evidence quality is as important as control implementation.
  • Baseline guidance identifies recurring evidence families: inventories, plans, and registers.
  • Governance-approved documents should be clearly identifiable and versioned.
  • Evidence should map directly to obligations and control measures.

Sources: ACN baseline reading guide

Core evidence families to maintain

1. Inventories

Maintain updated inventories of physical assets, services, systems, and applications relevant to the NIS scope.

2. Plans

Maintain current plans such as risk treatment, vulnerability management, continuity, disaster recovery, and crisis/incident-related plans where applicable.

3. Registers and records

Maintain traceable records of policy reviews, training activities, incident process actions, and governance decisions.

4. Governance-approved documents

Ensure documents requiring governing-body approval are formally approved, version-controlled, and retrievable.

Sources: ACN baseline reading guide, ACN baseline obligations determination

Audit-readiness operating model

Step Control objective Expected output
Evidence mappingLink each obligation to documentary proofObligation-to-evidence matrix
Version governanceEnsure document lifecycle traceabilityVersion log and approval history
AccessibilityEnable rapid retrieval for checks/auditsStructured evidence repository
Completeness checksDetect missing or stale evidencePeriodic gap assessment report

Sources: ACN baseline reading guide

90-day implementation checklist

  1. Build an obligation-to-evidence matrix by NIS control family.
  2. Standardize document naming, ownership, and versioning rules.
  3. Reconcile all governance-approved documents against required approvals.
  4. Set periodic evidence freshness checks with escalation for stale artifacts.
  5. Run an internal mock audit focused on retrieval speed and completeness.

FAQ

Are evidence requirements limited to policies?

No. Official guidance includes inventories, plans, and operational registers in addition to policy artifacts. Source: ACN baseline reading guide

What makes evidence audit-ready?

Evidence should be complete, current, traceable to obligations, and retrievable with clear ownership and approval history. Source: ACN baseline reading guide

Which documents typically need governance approval?

Details are defined in official baseline documentation, including dedicated sections on governance-approved document sets. Sources: ACN baseline reading guide, ACN baseline obligations determination

Aegister provides NIS2 compliance support including evidence framework design and audit preparation guidance.

Related guides in this series

Official sources

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