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Understanding the Purpose of ISMS Audits and Reviews
Why Audits Are a Core Requirement of ISO 27001
Audits are required to verify whether an organisation’s ISMS is functioning, effective, and aligned with ISO 27001 requirements. They provide independent evidence that policies, controls, and processes are not just documented but actually operating. Without audits, an organisation cannot demonstrate conformity to the standard and cannot maintain certification.
How Audits Support Continual Improvement
Audits highlight issues, inefficiencies, and areas for improvement. They help leadership understand whether risk management is effective, whether controls are working as expected, and whether new risks have emerged. Opportunities for improvement discovered during audits feed directly into corrective actions and continual improvement cycles required under Clause 10.
Difference Between Audits, Reviews, and Monitoring Activities
Audits are structured evaluations of compliance.
Management reviews are strategic assessments performed by top management under Clause 9.3.
Monitoring activities are operational checks performed regularly to ensure controls are functioning. All three work together to keep the ISMS healthy, effective, and continually improving.
Types of ISO 27001 Audits
First-Party Audits (Internal Audits)
Internal audits are performed by the organisation itself or by independent internal auditors to verify conformity with ISO 27001. These are mandatory under Clause 9.2 and must be performed at planned intervals.
Second-Party Audits (Customer or Supplier Audits)
These audits are initiated by customers or partners who want assurance that your ISMS is effective and that sensitive data is protected. They are common in SaaS, finance, healthcare, and supply chain organisations.
Third-Party Audits (Certification Audits)
Certification audits are performed by accredited certification bodies. These determine whether you meet ISO 27001 requirements and whether certification can be issued or maintained.
When Each Audit Type Is Required
Internal audits: annually or more frequently depending on risk.
Second-party audits: driven by contracts, customer expectations, or security questionnaires.
Certification audits: during initial certification, surveillance years, and recertification cycles.
What Evidence Each Audit Typically Examines
Auditors commonly review:
- Policies and procedures
- Risk assessments and treatment plans
- Annex A control evidence
- Logs, monitoring reports, and metrics
- Training records
- Incident response documentation
- Supplier evaluations
- Internal audit results
- Management review minutes
The ISO 27001 Audit Lifecycle
Annual Audit Planning and Risk-Based Scheduling
Internal audits must follow a documented audit program. This program outlines when audits occur, what areas will be audited, and which risks determine audit frequency. High-risk areas (cloud infrastructure, supplier management, access control) are audited more frequently.
Audit Preparation: Scope, Criteria, and Checklists
Preparation involves defining:
- Audit scope: processes, departments, locations
- Audit criteria: ISO 27001 requirements, internal policies, Annex A controls
- Audit methods: interviews, sampling, evidence review
Checklists based on Clauses 4–10 and Annex A simplify preparation and ensure the audit is comprehensive.
Conducting the Audit: Interviews, Sampling, and Evidence Review
Auditors interview employees, observe processes, and request evidence. They use sampling techniques to examine a subset of activities, such as reviewing incident logs, user access reviews, or change management tickets.
Audit Reporting and Findings
After the audit, findings are documented. These include:
- Conformities
- Nonconformities
- Observations
- Opportunities for improvement (OFIs)
Each finding must be clear, evidence-based, and referenced to a clause in ISO 27001.
Corrective Actions and Verification
When nonconformities are identified, organisations must perform root cause analysis, implement corrective actions, and provide evidence. Auditors verify actions have been completed.
NCs vs OFIs (Nonconformities and Opportunities for Improvement)
Nonconformities require mandatory action.
OFIs are optional improvements but often help strengthen future audits.
The Five-Step Audit Process Explained
Step 1 – Audit Initiation and Planning
Auditors establish the audit plan, identify audit objectives, confirm scope, allocate resources, and share schedules with involved teams.
Step 2 – Document Review
Auditors examine policies, procedures, risk assessments, SoA, and monitoring activities to determine whether ISMS design meets ISO 27001 requirements before testing operations.
Step 3 – On-Site or Remote Audit Activities
Auditors conduct interviews, review logs, sample controls, validate procedures, and determine whether controls are operating effectively. Evidence sampling is used to confirm consistency.
Step 4 – Reporting and Findings
The audit report includes all findings, classifications of nonconformities, and recommendations for improvement. The organisation must respond with corrective action plans.
Step 5 – Follow-Up and Closure
Corrective actions are validated. When all issues are resolved, the audit is formally closed. Certification audits move to decision-making by the certification body.
Internal Audit Requirements Under ISO 27001 (Clause 9.2)
How to Develop an Internal Audit Program
A compliant audit program must:
- Define audit frequency
- Assign auditors and responsibilities
- Establish scope and methodology
- Address risk-prioritised audit scheduling
- Document audit criteria
The audit program must be updated as the ISMS evolves.
Selecting Qualified Internal Auditors
Auditors must understand ISO 27001, audit techniques, and the systems they evaluate. They must also be competent in evidence gathering, interviewing, and reporting.
Ensuring Impartiality and Objectivity
Auditors cannot audit their own work. Independence is critical to ensuring valid audit results.
When to Use External Internal Auditors
Organisations may use external auditors when internal expertise is limited, when teams are small, or when impartiality cannot be guaranteed.
Evidence Required for Internal Audits
Evidence commonly includes:
- Change control logs
- Access reviews
- Incident reports
- Backup test results
- Training records
- Monitoring reports
- Policy acknowledgements
Management Review Requirements (Clause 9.3)
What Must Be Reviewed by Top Management
Top management must regularly review:
- ISMS performance
- Risk status
- Incident trends
- Control effectiveness
- Resource requirements
- Opportunities for improvement
- Alignment with business objectives
Inputs Required for the Management Review
Inputs must include:
Audit Results
Internal and external audit outcomes.
Nonconformities
Corrective actions and root cause analysis.
Risk Assessment Updates
New risks, residual risks, and risk treatment progress.
Control Performance
Monitoring outputs, metrics, KPIs, and incidents.
Resource Needs
Budget, staffing, training, and tooling requirements.
Outputs Required — Decisions, Improvements, and Actions
Management review outputs must include decisions on:
- Changes to the ISMS
- Improvement initiatives
- Resource allocation
- Risk acceptance or escalation
- Policy updates
How Often Management Reviews Must Occur
ISO 27001 requires management reviews at planned intervals, typically annually. High-risk or rapidly evolving organisations may conduct them quarterly.
Steps for ISO 27001 Certification Audits (Stage 1 and Stage 2)
Pre-Certification Readiness Assessment
A pre-certification readiness assessment confirms whether documentation, evidence, and ISMS governance are mature enough for Stage 1.
Stage 1 Audit — Documentation and ISMS Design Review
Stage 1 examines whether ISMS documentation meets ISO requirements.
What Auditors Look For in Stage 1
Auditors focus on:
- ISMS scope
- Risk assessment methodology
- Risk register
- SoA
- Policies and procedures
- Internal audit results
- Management review minutes
If major gaps exist, Stage 2 cannot begin.
Stage 2 Audit — Full ISMS Implementation Review
Stage 2 verifies operational effectiveness. Auditors check whether controls are working and whether staff follow documented processes.
How Evidence Sampling Works
Auditors select samples of activities such as:
- Access requests
- Change tickets
- Incident logs
- Vulnerability scans
- Supplier evaluations
Team Interviews and Operational Validation
Employees are interviewed to validate understanding of processes, responsibilities, and security practices.
Certification Decision Process
The certification body reviews all findings before issuing an ISO 27001 certificate. Certification is valid for three years.
The Six Stages of the ISO 27001 Certification Process
Stage 1 — Define ISMS Scope and Requirements
Identify boundaries, stakeholders, legal obligations, and assets.
Stage 2 — Conduct Risk Assessment and Select Controls
Perform assessments and build the SoA and RTP.
Stage 3 — Implement ISMS and Required Documentation
Roll out controls, policies, processes, and evidence management.
Stage 4 — Perform Internal Audit and Management Review
Confirm readiness before external certification audits.
Stage 5 — Undergo Stage 1 and Stage 2 External Audits
Certification auditors validate the ISMS design and operation.
Stage 6 — Receive Certification and Begin Surveillance Cycle
Certification is issued, followed by Year 1 and Year 2 surveillance audits.
Surveillance and Recertification Audits
Year 1 and Year 2 Surveillance Audit Requirements
Surveillance audits confirm continuous compliance. They are narrower in scope than Stage 2 but still require updated evidence, risk assessments, metrics, and corrective actions.
What Auditors Verify During Surveillance
Auditors check:
- Control performance
- Monitoring and measurement
- Risk updates
- Incident management
- Internal audits
- Management reviews
- Documentation currency
Recertification Audit at Year 3
The recertification audit is more extensive and reassesses the ISMS holistically.
Evidence Depth and Scope Reassessment
Auditors revalidate:
- Scope
- Risk treatment
- SoA
- Documentation
- Long-term control effectiveness
How Often the ISMS Must Be Reviewed and Improved
Required Frequency for Internal Audits
Internal audits must occur annually at minimum. High-risk areas may require more frequent review.
Required Frequency for Management Reviews
Management reviews are typically annual but may occur more often if risk levels or organisational changes require it.
Continuous Improvement Expectations
ISO 27001 requires continual improvement. This includes updating processes, closing audit findings, improving efficiencies, and maturing the ISMS over time.
Common Audit Challenges and How to Avoid Them
Missing or Outdated Documentation
Old policies, obsolete procedures, or incomplete evidence lead to nonconformities. Documents must always reflect current practices.
Poorly Defined Scope or Risk Assessment Criteria
Scope errors cause major audit failures. Risk criteria must be clear, consistent, and applied uniformly.
Not Maintaining Evidence Throughout the Year
Evidence cannot be fabricated at audit time. It must be collected continuously.
Failing to Track Corrective Actions Properly
Corrective actions must be documented, assigned, implemented, and validated.
Overreliance on External Consultants
Consultants can assist, but internal ownership is essential. Auditors expect employees — not consultants — to understand the ISMS.
Best Practices for a Smooth ISO 27001 Audit
Preparing Audit Trails and Evidence in Advance
Evidence should be stored in a structured system that auditors can navigate easily. ISMS platforms reduce audit stress significantly.
Ensuring Employee Competence Before Interviews
Employees must understand policies, follow processes, and be able to explain their responsibilities during audits.
Keeping Policies and Procedures Up to Date
Policies should match actual practice. Discrepancies result in nonconformities.
Using Audit Management Tools for Efficiency
Platforms help automate evidence collection, track audit findings, assign corrective actions, and maintain control performance dashboards.
Strengthen Your Audit and Review Process with Hicomply
ISO 27001 audits can be complex, time-consuming, and stressful without the right systems in place. Hicomply streamlines internal audits, evidence collection, management reviews, and certification preparation with automated workflows, built-in templates, and real-time ISMS dashboards. Book a demo to see how Hicomply removes complexity and helps you stay audit-ready all year.
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