In this ultimate how to implement guide to ISO 27001 Annex A 5.35 Independent Review of Information Security, you will learn directly from an ISO 27001 Lead Auditor:
- The requirement of the control
- The required implementation steps
- The minimum requirement
I am Stuart Barker, the ISO 27001 Lead Auditor and author of the Ultimate ISO 27001 Toolkit.
Using over 30 years of industry experience across hundreds of audits, I’m giving you the exact templates, walkthroughs, and practical examples you need to achieve ISO 27001 certification.
Table of contents
- 1. Formally Define ‘Independence’ Criteria
- 2. Establish a ‘Hard’ Review Schedule
- 3. Define ‘Significant Change’ Triggers
- 4. Vet Reviewer Competence
- 5. Execute Technical Reality Checks
- 6. Conduct Physical and Personnel Interviews
- 7. Integrate Penetration Testing Results
- 8. Produce Uncensored Audit Reports
- 9. Track Corrective Actions to Closure
- 10. Verify Remediation Effectiveness
- ISO 27001 Annex A 5.35 SaaS / GRC Platform Implementation Failure Checklist
Implementing ISO 27001 Annex A 5.35 is a critical assurance mandate requiring the objective, independent assessment of information security controls by competent reviewers separated from the implementation process. This control forces organizations to valid technical reality against documentation, providing the business benefit of unbiased validation, reduced blind spots, and defensible regulatory compliance.
ISO 27001 Annex A Independent Review of Information Security Implementation Checklist
Use this implementation checklist to achieve compliance with ISO 27001 Annex A 5.35. This control demands that your information security practices be audited by objective, competent reviewers who are technically capable of testing the reality of your controls, rather than simply reading your policy documents.
1. Formally Define ‘Independence’ Criteria
Control Requirement: Ensure the reviewer has no conflict of interest with the area being reviewed. Required Implementation Step: Create a policy statement explicitly barring IT managers from auditing their own infrastructure and C-levels from auditing their own governance decisions. Define “Independence” as: “A reviewer who has not designed, implemented, or managed the control within the last 12 months.”
Minimum Requirement: A signed ‘Conflict of Interest’ declaration for every internal or external reviewer.
2. Establish a ‘Hard’ Review Schedule
Control Requirement: Reviews must occur at planned intervals. Required Implementation Step: Publish an annual audit calendar that is approved by Top Management and cannot be moved by operational teams. Schedule reviews to occur before external certification audits to allow time for remediation, covering all 93 controls over a 3-year cycle (at minimum).
Minimum Requirement: A published 12-month audit schedule with assigned dates and named reviewers.
3. Define ‘Significant Change’ Triggers
Control Requirement: Conduct reviews when significant changes occur. Required Implementation Step: Update your Change Management Policy to automatically trigger an independent security review for specific events: major infrastructure migrations (e.g., on-prem to Cloud), new product launches, or mergers/acquisitions. Do not wait for the annual cycle.
Minimum Requirement: A “Post-Implementation Review” step in your Change Management procedure for high-impact changes.
