9 Mistakes to Avoid During ISO/IEC 27001 Audits of Information Security Management Systems

In the ever-evolving landscape of information security, achieving ISO 27001 compliance is crucial for organizations looking to safeguard sensitive data and enhance their overall security posture. With over 25 years of experience as an ISMS (Information Security Management System) Lead Auditor, having conducted hundreds of audits in 50+ countries across five continents and certified numerous ISMS auditors worldwide, I am confident that the role of the auditor extends far beyond simply checking boxes.

Effective auditing requires a deep understanding of the organization’s context, a commitment to integrity, and the ability to offer actionable insights that drive improvement. This article also contains examples and lessons learned from audits I have personally conducted over more than two decades in the field.

However, common pitfalls can undermine the auditing process and hinder the organization's compliance journey. Here are some key missteps often encountered during ISO 27001 audits, along with real-life auditing examples from my auditing experience illustrating why avoiding them is crucial:

1. Failing to Verify Actual Practices

An organization might have flawless documentation outlining excellent security measures, yet interviews with staff could reveal that most employees are unaware of the procedures. Relying solely on documents without verifying implementation can lead to significant gaps in compliance.

During an audit of a government agency in Central Asia, the documented access control policy was comprehensive. However, my interaction with system users showed they had never received training on it. This mismatch revealed a critical awareness gap and prompted corrective action on communication and training.

2. Focusing on Trivial Issues Over Critical Risks

A common pitfall is when auditors emphasize minor issues and overlook major risks. In a financial institution audit in the USA, the previous auditor flagged outdated templates and formatting inconsistencies in policies, while completely missing a critical flaw, unrestricted access to the core banking application logs.

During assessment, I discovered that system administrators had direct access to modify or delete transaction logs without requiring dual authorization or audit trails. Additionally, critical event logs were not being backed up or monitored, meaning any unauthorized activity could be erased without detection. This represented a significant threat to data integrity and fraud prevention, especially in a financial institution handling high-value transactions.

3. Pushing Personal Opinions as Standards

Some auditors insist on specific methods or biases regarding ISMS management, leading to unrealistic expectations.

In an audit of a large telecom in APAC region, a local auditor in my team insisted all data be encrypted, regardless of risk level or business impact. The client was understandably frustrated. They weren't non-compliant; they were making risk-based decisions, which is exactly what ISO 27001 encourages. I later guided my auditor on aligning controls to actual risk and business needs, not individual preferences.

4. The Vague Verdict - Leaving Clients Guessing

"Lack of control over medical records." That was the extent of a non-conformance I found in a previous audit report for a group of hospitals. No specifics, no examples, no clear path forward. 

When I revisited their situation, I discovered the real issue: medical staff were accessing patient files without proper logging, creating both privacy and compliance risks. Once we identified specific incidents, the hospital could create a targeted action plan.

I normally say it clearly to my fellow auditors: if you can't explain the problem clearly enough for someone to fix it, you haven't done your job. Specific, actionable feedback transforms audit findings from frustrations into roadmaps for improvement.

5. Allowing Budget Constraints to Undermine the Audit

Budget constraints can lead to rushed audits, often failing to cover essential aspects. Budget constraints can lead to rushed or superficial audits, particularly in internal assessments.

During audit of a seaport in Australia, I saw the record of an ISMS internal audit, which was conducted in a single day with only one auditor, whereas there were 10 departments within the scope of the Internal/external audit. It was revealed during the audit that several areas had been skipped due to time constraints.

6. Overlooking the Organization’s Context

Security doesn't exist in a vacuum. I learned this lesson specially while auditing a logistics company in Africa operating in a politically unstable region. Previous auditors had evaluated their business continuity planning (Availability compromise) using generic benchmarks, completely ignoring the reality of supply chain disruptions & regional instability.

By understanding their actual operating environment, we could assess whether their ISMS truly addressed the risks they faced every day.

7. Using Checklists as the Sole Evaluation Tool

An auditor might mechanically tick off boxes on a checklist without considering the broader context, which can lead to missed insights.

In an audit of an Oil & Gas organization, I found one of my audit team members used a rigid checklist and was fully focused only on filling it - not on reviewing the evidence or listening to the answers, seriously lacking in his focus on building an actual audit trail. Hence, he missed a glaring gap like contractors were connecting USBs to production systems without logging activity.

My contextual questioning revealed this, leading to a serious finding which definitely helped the organization to improve upon their security posture.

8. Combining Auditing and Consultancy Roles

Offering consultancy immediately after auditing creates conflicts of interest and undermines objectivity.

After a surveillance audit in Europe, the client shared that a previous auditor from another certification body began recommending specific advice on how to close the findings that our audit team had raised. This behavior blurred the line between independent auditing and consultancy, raising concerns about impartiality. Our team maintains a strictly objective stance, focusing solely on the audit criteria and leaving any implementation support to independent parties.

9. Failing to Assess the Effectiveness of Controls

Verifying that controls exist is not enough; testing their effectiveness is key.

In the audit of a national stock exchange in South America - an organization where confidentiality, integrity and availability of information are paramount - we reviewed the control implementation around privileged access.

Although a policy existed requiring monthly reviews of privileged access logs, no actual evidence of periodic reviews or signoffs was available. A sample of system logs (through already installed tools) showed repeated access attempts outside business hours that had not been investigated or flagged.

This highlighted a gap between documented controls and operational oversight, particularly in a high-risk, time-sensitive environment.

Conclusion: The Real Goal is to Build Resilient Organizations

Achieving ISO 27001 compliance is not merely about fulfilling requirements: it's about cultivating a robust security culture within an organization. Our job as auditors isn't to find fault; it's to help organizations become more resilient by identifying gaps, providing actionable insights and ensuring that controls are not only in place but also functioning as intended.

Every finding should feel like a gift, not a punishment. Every recommendation should feel achievable, not overwhelming. Effective auditing plays a pivotal role in this cultural transformation process.

The best audits I've conducted weren't the ones where I found the most non-conformances. They were the ones where, months later, the organization called to thank me because our assessment helped them prevent a real security incident or improve their operational efficiency.

In our interconnected world, where a single security breach can destroy decades of reputation-building, the human element in auditing has never been more critical. We're not just evaluating compliance; we're helping organizations protect what matters most to them while building that essential security culture from the ground up.

Remember: behind every policy, every control and every procedure there are real people trying to do their jobs well while keeping their organization secure. When we approach auditing with empathy, curiosity and genuine desire to help, we transform what could be an adversarial process into a collaborative journey toward better security.

The goal isn't just compliance, it's building organizations that can face tomorrow's challenges with confidence, supported by a security culture that makes protection everyone's responsibility.