What is an ISO audit?

Although often referred to as ISO audit, there is technically no such thing. What people mean by an ISO audit is an audit of a management system implemented to meet an ISO standard. These audits are either conducted internally, by a trained member of staff within the organisation, or externally by an independent, third-party certification body such as DNV. 

Regardless of who performs it, the audit is an essential part of achieving and maintaining ISO certification, ensuring that the implemented management system continues to meet the requirements of the relevant standard.  

ISO Audit: meaning and definition

A wide range of ISO management system standards now exist, covering areas such as quality management, information security, environmental management, occupational health and safety, and many others. These standards are commonly referred to by their specific numbers, such as ISO 9001, ISO/IEC 27001, ISO 14001 and ISO 45001 respectively.

An ISO audit is a systematic, evidence-based process used to determine how well an organisation’s management system meets the requirements of a relevant ISO standard. By gathering and evaluating objective audit evidence, the process assesses the effectiveness of the organisation’s implementation and highlights the opportunities for improvement.  

Why is an ISO audit important?

Choosing to implement a management system aligned with an ISO standard – and pursuing certification – is typically a voluntary action by an organisation. In some cases, certification may however be required to comply with local or national regulations. More commonly, certification serves as a ‘ticket to trade’, as customers, supply chain partners, and other stakeholders increasingly require evidence that an organisation follows best practice and is committed to continual improvement.  This applies across areas such as product and service quality, environmental performance, occupational health and safety, and information security. Implementing ISO standards can also support broader sustainability goals, helping organisations demonstrate alignment with ESG principles and contribute to relevant UN Sustainable Development Goals (SDGs).  

ISO audits are an essential part of the certification process because they are designed to monitor and ensure that an organisation's processes align with the defined requirements of an ISO standard and verify that the implemented management system is effective and efficient. Audits, both internal and external, help identify risks and non-conformities, as well as providing opportunities to continually improve the system.  

Types of ISO audit

There are two main types of ISO audits: internal and external, or certification audits.  

Internal audits

Internal audits, also referred to as first-party audits, are conducted by the organisation’s own trained internal auditors to support self-assessment and drive continual improvement. All ISO management system standards require organisations to perform internal audits. In essence, each organisation must plan, establish, implement and maintain an audit programme, defining the audit frequency, methods, responsibilities, planning steps, and reporting requirements. Internal audits are an important management tool, helping organisations monitor performance, verify conformity with a chosen ISO standard, and identify improvement opportunities. 

ISO 19011 provides valuable guidance on the audit process, including principles and best-practice techniques.  

The first internal audit typically takes place early in the implementation journey. A complete cycle of internal audits is also required before an organisation can proceed to a formal certification audit. 

Many organisations also find it beneficial to undertake a pre-assessment or gap analysis conducted by a certification body or registrar. The purpose of this optional process is to identify potential non-conformance or weaknesses in the management system, allowing the organisation to address them before beginning the formal, accredited certification process. 

Certification audits

Certification audits, also referred to as external audits, are conducted by a third party certification body to verify that the implemented management system conforms to the requirements of a specific ISO standard. A successful certification audit will result in the organisation’s management system receiving a certificate demonstrating to stakeholders that the system has been independently evaluated and confirmed as effective. 

Audits can be time-consuming and costly, so organisations that have adopted several management systems may benefit from conducting an integrated management system audit. Most widely adopted ISO management system standards share a harmonised structure, use common terminology, and include the same core requirements. This alignment improves usability and enables organisations to combine some or all of their management systems into a single, integrated system, streamlining audits and improving overall efficiency. 

Mistakes to avoid in ISO audits

Implementing standardised management systems is widely regarded as a modern and effective way to do business, but it can be a significant step for a company to take. Audit quality often suffers when there are insufficient planning and preparation, poor communication, limited involvement of relevant personnel, and inadequate documentation and record keeping. Once an audit has been completed, failure to address identified nonconformities and implement corrective actions is another common pitfall to avoid.  

The competence of an auditor or audit team is a critical factor in ensuring that an audit is both effective and valuable. When developing the audit programme, organisations should assign auditors who have the appropriate training and competence for the areas they will be auditing. Ideally, auditing team members will have successfully completed an internal auditor course provided by the certifying body or other training provider. DNV offers a range of training for internal lead auditors and auditor team members.

A well-trained audit team can help prevent many of the common mistakes that can occur before, during, and after an audit. The importance of auditor quality and competence should never be underestimated. Audits often bring together individuals across different levels of seniority and in some cases the process may be perceived as intrusive or as a challenge to someone’s established methods or performance. For this reason, completing a structured internal auditor certification course can be invaluable, ensuring that auditors develop the confidence, professionalism, and interpersonal skills needed to manage sensitive situations constructively and maintain a productive, collaborative audit environment. 

By understanding the purpose, value, standards, types, and common pitfalls of ISO audits, organisations can better prepare for these assessments and gain maximum benefit from them, ultimately strengthening their management systems and enhancing overall performance.