ISO 27001:2022 Annex A 5.35 – Independent Review of Information Security Explained

Security programmes drift when they are never challenged.

Annex A 5.35 exists to ensure organisations periodically subject their information security arrangements to independent review, so weaknesses are identified early and improvement is driven by evidence rather than assumption.

This control is about objective assurance, not self-validation.

ISO 27001

Quick Guide: Annex A 5.35 at a Glance

Annex A 5.35 of ISO 27001:2022 focuses on the independent review of information security.

At a practical level, this means:

  • Reviewing information security independently of day-to-day operation
  • Assessing whether policies, controls, and processes remain effective
  • Identifying gaps, weaknesses, and improvement opportunities
  • Conducting reviews at planned intervals and after significant change
  • Reporting findings to appropriate management

The control does not mandate who must perform the review or how often it must occur. It expects reviews to be independent, competent, and proportionate to risk.

In-Depth Guide to Annex A 5.35

What Is Annex A 5.35 and Why Does It Matter?

Over time, information security controls can:

  • Become outdated
  • Drift from documented intent
  • Be bypassed by new processes or technologies
  • Remain in place long after risks have changed

Internal confidence alone is not a reliable indicator of effectiveness.

Annex A 5.35 ensures organisations step back and assess security objectively, using people who are not responsible for operating the controls being reviewed.

This provides:

  • Independent assurance to management
  • Early identification of weaknesses
  • Evidence for improvement and investment decisions
  • Confidence that security remains aligned with objectives

Without independent review, organisations often discover issues only during incidents or external audits.

How to Implement Annex A 5.35 Effectively

A pragmatic approach to Annex A 5.35 typically includes the following elements.

1. Define the Scope of Independent Review

Reviews should cover areas that materially affect information security, such as:

  • Information security policies
  • Topic-specific policies and procedures
  • Implemented controls
  • Operational practices
  • Alignment with security objectives

Scope should be risk-based rather than exhaustive.

2. Ensure Reviewer Independence

Independence is central to this control.

Reviews may be performed by:

  • Internal auditors
  • Staff from other departments with no operational responsibility
  • External consultants or assurance providers

The key requirement is that reviewers are not reviewing their own work and can provide an unbiased assessment.

3. Ensure Reviewer Competence

Whoever performs the review should have:

  • Sufficient understanding of information security principles
  • Knowledge of the organisation’s context
  • Ability to assess people, process, and technology

Independence without competence adds little value.

4. Conduct Reviews at Planned Intervals

Independent reviews should be planned rather than reactive.

Frequency is typically influenced by:

  • Organisational size and complexity
  • Risk exposure
  • Regulatory or contractual expectations

Regular review prevents slow degradation of controls.

5. Perform Ad-Hoc Reviews When Change Occurs

Annex A 5.35 recognises that some situations justify additional review, such as:

  • Significant security incidents
  • Major organisational or system change
  • Introduction of new products or services
  • Changes in legal or regulatory requirements
  • Material updates to security controls or processes

Change introduces risk — review provides reassurance.

6. Record, Report, and Act on Findings

Review outputs should be:

  • Documented
  • Reported to appropriate management
  • Used to drive corrective or improvement actions

A review that produces no action has limited value.

In-Depth Guide to Annex A 5.1

What is Annex A 5.1 and Why Does It Matter?

  • What the organisation values
  • How security decisions are approached
  • Where accountability sits
  • Aligns security with business objectives
  • Supports proportionate, risk-based decisions
  • Provides a reference point during incidents and disputes
  • Creates consistency without bureaucracy

How to Implement Annex A 5.1 Effectively

1. Define a Comprehensive Information Security Policy
  • Scope: What the policy applies to (systems, data, people).
  • Objectives: Why security is important for the business.
  • Roles & Responsibilities: Who is accountable for security.
  • Key Principles: Risk management, access control, and data protection.
2. Secure Senior Management Approval
  • Review and approve policies.
  • Ensure resources are allocated for implementation.
  • Lead by example in enforcing security policies.
3. Communicate and Train Employees
  • Include security policies in onboarding and ongoing training.
  • Ensure policies are easily accessible to all employees.
  • Encourage acknowledgment and acceptance of security responsibilities.
4. Regular Review & Continuous Improvement
  • Set a schedule for periodic policy reviews (at least annually).
  • Update policies based on business changes, new threats, or regulatory updates.
  • Conduct audits to ensure compliance and effectiveness.
5. Integrate Policies into the ISMS
  • Use it to develop more detailed security procedures.
  • Ensure policies align with other Annex A controls and broader risk management practices.
Key Differences: ISO 27001:2013 vs ISO 27001:2022
AspectISO 27001:2013ISO 27001:2022
Control StructureTwo separate controls: 5.1.1 & 5.1.2Merged into one control (5.1)
Implementation GuidanceLess prescriptiveMore detailed guidance for policy creation and alignment
Awareness & TrainingNot explicitly mentionedExplicitly requires policies to be part of training programmes
Attributes TableNot includedew attributes table for mapping policies to industry terms
Common Challenges & How to Overcome Them
  • Challenge: Employees don’t follow security policies.
  • Solution: Make policies practical and relevant to daily work. Use real-world examples in training.
  • Challenge: Policies are outdated or too generic.
  • Solution: Schedule annual reviews and update policies based on real threats and business changes.
  • Challenge: Policies are written in technical jargon.
  • Solution: Use plain language that all employees can understand.
  • Challenge: Lack of leadership buy-in.
  • Solution: Show how weak security affects business objectives—costs of breaches, loss of client trust, and legal penalties.
Final Recommendations
  • Make security policies living documents—review, refine, and update regularly.
  • Use policy training and awareness to create a security-conscious workforce.
  • Ensure policies are accessible, relevant, and easy to understand.
  • Keep policies aligned with business strategy and regulatory requirements.
  • Engage leadership in driving security culture from the top down.

Practical Considerations

Independent review does not need to be heavy-weight.

Effective reviews are often:

  • Focused on high-risk areas
  • Evidence-based
  • Clear about what is working and what is not
  • Constructive rather than fault-finding

The purpose is improvement, not blame.

This control complements — but does not replace —:

  • Internal audit
  • Management review
  • Certification audits

Each provides a different perspective and level of assurance.

Common Challenges and How to Overcome Them

  • Treating review as a compliance exercise
  • Focus on effectiveness and improvement
  • Using reviewers who lack independence
  • Separate review responsibility from operation
  • Ignoring review findings
  • Assign ownership and track actions
  • Only reviewing after problems occur
  • Plan regular, proactive reviews

Security programmes stagnate when they are never challenged.

In-Depth Guide to Annex A 5.1

What is Annex A 5.1 and Why Does It Matter?

  • What the organisation values
  • How security decisions are approached
  • Where accountability sits
  • Aligns security with business objectives
  • Supports proportionate, risk-based decisions
  • Provides a reference point during incidents and disputes
  • Creates consistency without bureaucracy

How to Implement Annex A 5.1 Effectively

1. Define a Comprehensive Information Security Policy
  • Scope: What the policy applies to (systems, data, people).
  • Objectives: Why security is important for the business.
  • Roles & Responsibilities: Who is accountable for security.
  • Key Principles: Risk management, access control, and data protection.
2. Secure Senior Management Approval
  • Review and approve policies.
  • Ensure resources are allocated for implementation.
  • Lead by example in enforcing security policies.
3. Communicate and Train Employees
  • Include security policies in onboarding and ongoing training.
  • Ensure policies are easily accessible to all employees.
  • Encourage acknowledgment and acceptance of security responsibilities.
4. Regular Review & Continuous Improvement
  • Set a schedule for periodic policy reviews (at least annually).
  • Update policies based on business changes, new threats, or regulatory updates.
  • Conduct audits to ensure compliance and effectiveness.
5. Integrate Policies into the ISMS
  • Use it to develop more detailed security procedures.
  • Ensure policies align with other Annex A controls and broader risk management practices.
Key Differences: ISO 27001:2013 vs ISO 27001:2022
AspectISO 27001:2013ISO 27001:2022
Control StructureTwo separate controls: 5.1.1 & 5.1.2Merged into one control (5.1)
Implementation GuidanceLess prescriptiveMore detailed guidance for policy creation and alignment
Awareness & TrainingNot explicitly mentionedExplicitly requires policies to be part of training programmes
Attributes TableNot includedew attributes table for mapping policies to industry terms
Common Challenges & How to Overcome Them
  • Challenge: Employees don’t follow security policies.
  • Solution: Make policies practical and relevant to daily work. Use real-world examples in training.
  • Challenge: Policies are outdated or too generic.
  • Solution: Schedule annual reviews and update policies based on real threats and business changes.
  • Challenge: Policies are written in technical jargon.
  • Solution: Use plain language that all employees can understand.
  • Challenge: Lack of leadership buy-in.
  • Solution: Show how weak security affects business objectives—costs of breaches, loss of client trust, and legal penalties.
Final Recommendations
  • Make security policies living documents—review, refine, and update regularly.
  • Use policy training and awareness to create a security-conscious workforce.
  • Ensure policies are accessible, relevant, and easy to understand.
  • Keep policies aligned with business strategy and regulatory requirements.
  • Engage leadership in driving security culture from the top down.

Final Recommendations

Annex A 5.35 is about maintaining objectivity over time.

When independent reviews are applied effectively:

  • Weaknesses are identified earlier
  • Security remains aligned with business change
  • Management decisions are better informed
  • Continuous improvement becomes practical

Security assurance should not rely on confidence alone.
Annex A 5.35 ensures organisations verify, challenge, and improve their information security before others do.

In-Depth Guide to Annex A 5.1

What is Annex A 5.1 and Why Does It Matter?

  • What the organisation values
  • How security decisions are approached
  • Where accountability sits
  • Aligns security with business objectives
  • Supports proportionate, risk-based decisions
  • Provides a reference point during incidents and disputes
  • Creates consistency without bureaucracy

How to Implement Annex A 5.1 Effectively

1. Define a Comprehensive Information Security Policy
  • Scope: What the policy applies to (systems, data, people).
  • Objectives: Why security is important for the business.
  • Roles & Responsibilities: Who is accountable for security.
  • Key Principles: Risk management, access control, and data protection.
2. Secure Senior Management Approval
  • Review and approve policies.
  • Ensure resources are allocated for implementation.
  • Lead by example in enforcing security policies.
3. Communicate and Train Employees
  • Include security policies in onboarding and ongoing training.
  • Ensure policies are easily accessible to all employees.
  • Encourage acknowledgment and acceptance of security responsibilities.
4. Regular Review & Continuous Improvement
  • Set a schedule for periodic policy reviews (at least annually).
  • Update policies based on business changes, new threats, or regulatory updates.
  • Conduct audits to ensure compliance and effectiveness.
5. Integrate Policies into the ISMS
  • Use it to develop more detailed security procedures.
  • Ensure policies align with other Annex A controls and broader risk management practices.
Key Differences: ISO 27001:2013 vs ISO 27001:2022
AspectISO 27001:2013ISO 27001:2022
Control StructureTwo separate controls: 5.1.1 & 5.1.2Merged into one control (5.1)
Implementation GuidanceLess prescriptiveMore detailed guidance for policy creation and alignment
Awareness & TrainingNot explicitly mentionedExplicitly requires policies to be part of training programmes
Attributes TableNot includedew attributes table for mapping policies to industry terms
Common Challenges & How to Overcome Them
  • Challenge: Employees don’t follow security policies.
  • Solution: Make policies practical and relevant to daily work. Use real-world examples in training.
  • Challenge: Policies are outdated or too generic.
  • Solution: Schedule annual reviews and update policies based on real threats and business changes.
  • Challenge: Policies are written in technical jargon.
  • Solution: Use plain language that all employees can understand.
  • Challenge: Lack of leadership buy-in.
  • Solution: Show how weak security affects business objectives—costs of breaches, loss of client trust, and legal penalties.
Final Recommendations
  • Make security policies living documents—review, refine, and update regularly.
  • Use policy training and awareness to create a security-conscious workforce.
  • Ensure policies are accessible, relevant, and easy to understand.
  • Keep policies aligned with business strategy and regulatory requirements.
  • Engage leadership in driving security culture from the top down.

The Annex Control Table

ISO 27001:2022 Organisational Controls
ISO 27001:2022 Technological Controls