External auditing vs internal auditing: what’s the difference?

ISO standards are crucial in today’s business landscape, helping businesses establish robust management systems and demonstrate their commitment to quality, environmental responsibility, and information security.

Businesses often undertake ISO audits to maintain compliance and continuously improve their processes. Regarding ISO auditing, there are two primary approaches: external and internal. This blog will explore the key differences between external and internal ISO auditing and help determine which approach best suits your business.

What is external auditing?

External auditing involves hiring independent auditors or certification bodies to assess your company’s compliance with ISO standards. These auditors are unbiased third parties with specialised expertise and knowledge of ISO requirements. They conduct thorough assessments, evaluating your processes, procedures, and documentation against the applicable ISO standard.

External audits provide an objective view of your compliance status and offer an unbiased assessment of your ISO management system. They are necessary for gaining ISO certification and instilling confidence in your clients and stakeholders.

The benefits of external auditing include the following:

• Independent and unbiased assessment: External auditors objectively evaluate your processes and systems
• Expertise and experience: Certified auditors possess in-depth knowledge of ISO standards and auditing practices
• Credibility and trust: External audits enhance your business’s credibility by demonstrating compliance with internationally reputable standards
• Benchmarking and best practices: Auditors can provide insights into industry best practices, helping you identify areas for improvement and benchmark against peers

What is internal auditing?

Internal auditing involves conducting audits by trained personnel within your business. These auditors are familiar with your business operations, policies, and processes. Internal audits focus on verifying compliance with ISO requirements, identifying gaps, and driving continuous improvement. Internal audits are a proactive tool to monitor and enhance your management system’s effectiveness, identify non-conformances, and implement corrective actions.

Businesses wishing to maintain their ISO management system standard must conduct internal audits of their system. This is also a necessary requirement to maintain their ISO certification. These internal audits can be conducted by trained personnel or qualified external consultants. Internal audits, conducted correctly, will allow for continuous improvement of the management system.

Organisations can conduct the internal audits necessary for improvement by having an in-house auditor trained to identify and act on non-conformances.

The benefits of internal auditing include the following:

• Ongoing monitoring and improvement: Internal audits enable regular evaluations of your processes, ensuring compliance and driving continual improvement
• Cost-effectiveness: Conducting internal audits can be more budget-friendly compared to hiring external auditors
• In-depth knowledge of business operations: Internal auditors possess a deep understanding of your business, allowing them to identify context-specific areas for improvement
• Building internal competence: Internal auditing helps develop internal expertise and knowledge of ISO standards within your business

You can read our blog here for further information about internal auditor training.

What are the differences and similarities between an internal and external audit?

Depending on the nature of your business, available resources and business objectives, an organisation may use the services of an external auditor to conduct their internal audits. However, this is not the same as having an external auditor conduct your certification audit on behalf of a certification body.

When an organisation hires an external auditor to conduct an internal audit, they will assess an organisation’s internal processes, control and compliance with specific standards or regulations. The external auditor, independent of the organisation, reviews its systems, procedures, and documentation to evaluate their effectiveness and identify areas for improvement to ensure compliance with internal policies and external requirements.

When an organisation is ready to seek certification, they engage with an external auditor from a certification body or registrar to conduct the certification audit. This holds a different purpose, as the external auditor’s role is to evaluate whether the organisation’s management systems, processes and controls align with the requirements of the standard being certified. They will perform on-site inspections to verify compliance. The outcome of a successful certification audit is the issuance of an official certification that demonstrates compliance.

Internal auditing is a requirement for all ISO management system standards to maintain compliance and the upkeep of their management systems. Regular internal audits enable organisations to assess their compliance with the requirements, identify gaps or non-conformities, and take corrective action to maintain or improve their system’s effectiveness.

Therefore, internal auditing is a requirement for organisations to monitor and evaluate the implementation of processes, procedures, and controls, which fosters a culture of continuous improvement.

Organisations may improve their overall performance, optimise their operations, foster stakeholder trust, and assure long-term success in a competitive business environment by offering an objective review of the system’s performance.

At IMSM, we provide internal auditor training courses for businesses that want to maintain the upkeep of their ISO management systems in adherence to the standard’s requirements.

We provide internal auditor training on the following ISO courses:

• ISO 9001 Quality Management System
• ISO/IEC 27001 Data Security
• ISO 45001 Occupational Health and Safety
• ISO 14001 Environmental Management
• ISO 13485 Medical Devices
• ISO 22301 Business Continuity
• ISO 50001 Energy Management
• ISO 22716 Cosmetics GMP
• ISO/IEC 20000 Information Technology
• AS 9100 Aerospace
• 2-Day Integrated Management System

Read more about how internal auditor training drives growth and success in our blog here.

I’m interested in internal auditor training; what next?

Auditing is critical to maintaining compliance and driving continuous improvement in your business. External audits provide independent validation and certification, while internal audits offer ongoing monitoring and improvement.

Ultimately, the decision depends on your business goals, available resources, and desired level of expertise. By carefully considering these factors, you can establish an effective ISO auditing strategy that best suits your business, ensuring long-term success and customer satisfaction.

You can contact us if you’re interested in learning more about how to become an internal auditor, and we’ll advise you on the next steps you need to take.