A.5.35 A.5 · Organisational Controls

A.5.35 — Independent review of information security

Review the IS approach and its implementation independently at planned intervals or when significant changes occur.

Also written as A5.35, Annex A 5.35, ISO 27001:2022 A.5.35, ISO27001 A.5.35.

Written by Jett N. · Last reviewed

What ISO 27001 A.5.35 requires

Independent review of information security is one of 37 Organisational Controls in ISO/IEC 27001:2022 Annex A. Review the IS approach and its implementation independently at planned intervals or when significant changes occur. Organisational controls are judged on governance rather than tooling: an auditor wants a named owner, an approval trail, and evidence the control is exercised on a defined cadence rather than written once and filed.

Audit evidence assessors look for

When preparing your Statement of Applicability (SoA) for A.5.35, gather artefacts such as:

  • Independent IS audit or review reports
  • Third-party auditor engagement records and scope
  • Audit programme and schedule
  • Management responses and corrective actions from audit findings

How A.5.35 maps to SOC 2 and NIST CSF

If you run more than one framework, the same evidence usually satisfies all of them. A.5.35 aligns with:

SOC 2: CC4.1 Ongoing and separate evaluations, CC4.2 Evaluating and communicating deficiencies

NIST CSF 2.0: GV.OV-03 Risk management performance measured, ID.IM-01 Improvements from evaluations

ISO 27001:2013 mapping

A.5.35 consolidates the following ISO 27001:2013 control(s): A.18.2.1. If you are transitioning an existing ISMS, map your prior evidence for these to A.5.35 in your updated SoA.

Map A.5.35 to NIST CSF & SOC 2 →
Crosswalk this control in the Control Mapper & Gap Assessment.
Document the risk →
Record treatment for gaps against A.5.35 in the Risk Register.

Related Annex A controls

A.5.36 Compliance with policies, rules and standards for information security A.5.27 Learning from information security incidents A.5.22 Monitoring, review and change management of supplier services A.8.29 Security testing in development and acceptance A.8.34 Protection of information systems during audit testing

See all 37 Organisational Controls →

Frequently asked questions

Is ISO 27001 A.5.35 mandatory?

Annex A controls are not mandatory in the abstract. Clause 6.1.3 requires you to compare your risk treatment plan against Annex A and justify, in the Statement of Applicability, any control you exclude. If your risk assessment surfaces a risk that A.5.35 addresses, excluding it needs a documented, risk-based rationale that an auditor will test.

How do auditors test ISO 27001 A.5.35?

In two passes. First design: does a documented control exist, is it owned, and does it address the risk? Then operating effectiveness: the auditor samples records from across the audit period to confirm the control actually ran. A Stage 2 audit will typically pull several samples, so evidence that only exists for the month before the audit is a common finding.

How often should A.5.35 be reviewed?

ISO 27001 sets no fixed interval — it requires review at "planned intervals" and after significant change. Annual review is the norm most certification bodies expect, with an out-of-cycle review triggered by incidents, major system changes, restructures, or new regulatory obligations. Record the review date and outcome either way; an undated control is treated as unreviewed.

What does ISO 27001 A.5.35 map to in SOC 2 and NIST CSF?

A.5.35 aligns with SOC 2 CC4.1, CC4.2 and NIST CSF GV.OV-03, ID.IM-01. Evidence gathered for one framework will usually satisfy the others, which is the basis for a test-once, satisfy-many control library.

What was A.5.35 in ISO 27001:2013?

A.5.35 consolidates 1 control(s) from the 2013 edition: A.18.2.1. When transitioning, re-point the existing evidence rather than rebuilding it — the underlying requirement has not changed materially.