We’ve entered an era of growing cyber risks and regulatory scrutiny, and every business feels the pressure to prove it’s on top of its compliance game. Today, one of the most effective ways to demonstrate control over your information security practices is by aligning with recognized security frameworks such as ISO 27001.
While achieving ISO 27001 certification is a strong competitive differentiator, the process itself is extensive and involves several types of audits, both internal and external. It also entails ongoing efforts to keep your information security management system (ISMS) performing as intended.
To pass these audits successfully, you need thorough preparation and a good understanding of each assessment stage. This guide will help you:
- Learn about different ISO 27001 audits and their purposes
- Anticipate the requirements for each
- Apply best practices for staying audit-ready
What are ISO 27001 audits?
ISO 27001 audits are formal assessments that evaluate how effectively your ISMS meets the requirements of the standard. Their purpose is to verify if your organization has implemented the necessary policies and controls to protect sensitive information, as well as assess and mitigate risks.
To maintain ISO 27001:2022 compliance, you have to undergo several audits during the three-year certification lifecycle, including:
- Internal audits, conducted by your own team or external consultants
- External audits, conducted by an accredited body
“
The stages of the audits can be best seen as proving that security is built into the business, not just bolted on. Each phase adds another layer of confidence that your ISMS isn’t only compliant but also continues to operate as it was designed.”
Consult the table below for a brief overview of all relevant ISO 27001 audit stages:
{{cta_withimage2="/cta-modules"}} | ISO 27001 compliance checklist
All about ISO 27001 internal audits
Regular internal audits are an ongoing ISO 27001 requirement listed in clause 9.2. These audits can be useful for identifying and addressing compliance gaps before the official certification process begins. They involve a structured examination of your ISMS before bringing in an accredited external auditor.
Typically, the ISO 27001 internal audit process involves:
- Conducting risk assessments
- Reviewing ISMS documentation
- Testing controls to verify they meet the intended outcomes
The audit can be conducted by hired external consultants or internal stakeholders. If it’s the latter, they need to remain objective and impartial throughout the review, which means they shouldn't audit areas they’re directly responsible for.
Common gaps and misinterpretations during ISO 27001 internal audits
Many organizations orient their internal audits more toward technical Annex controls, such as firewalls, encryption, and access logs, because they’re easier to measure definitively. This can be an oversight, as some of the most valuable internal findings during an ISO 27001 audit stem from governance, process and clause controls, where the ownership isn’t always clear.
For example, ownership of user offboarding often blurs between IT, HR, and security teams. HR knows when an employee leaves, IT manages system access, and security is responsible for oversight, yet no single team owns the process end-to-end.
For a productive internal audit cycle, make sure that your team reviews both human and procedural elements alongside technical controls.
Another common misinterpretation is that ISO 27001 requires all controls to undergo an internal audit every year. In practice, you only need an internal audit program that ensures all ISMS controls are reviewed over time, typically within the three-year certification cycle.
All about ISO 27001 external audits
To obtain an ISO 27001:2022 certificate, you must undergo an external audit conducted by an accredited certification body. There are various certification bodies (who have been audited against ISO/IEC 17021) you can partner with, depending on your location, including:
- ANSI National Accreditation Board (ANAB) for the U.S.
- Standards Council of Canada (SCC)
- Deutsche Akkreditierungsstelle GmbH (DAkkS) for Germany
- Comité Français d'Accréditation (Cofrac) for France
- Joint Accreditation System of Australia & New Zealand (JASANZ)
- United Kingdom Accreditation Service (UKAS)
- National Standards Authority of Ireland (NSAI)
- Accredia for Italy
ISO 27001 external audits can be split into three main stages:
- Initial certification audit (conducted in two phases)
- Surveillance audit
- Recertification audit
I. Initial certification audit
The Initial certification audit can take anywhere between 3 and 12 months, depending on your organization’s ISMS maturity, documentation quality, and ISO 27001 readiness.
To make the process smoother, set clear expectations with your auditor early on. Organizations often treat ISO 27001 as a box-checking exercise, but the most successful certification cycles come from open communication and a risk-focused approach. Be upfront with your auditor about any gaps in your ISMS and demonstrate how you’re addressing them. Most auditors expect honesty and accountability over surface-level perfection.
For instance, auditors don’t expect a 20-person startup to maintain the same level of documentation as a global enterprise. They'll be more concerned about whether the ISMS is right-sized for the organisation context and genuinely effective in protecting information assets from relevant risks.
Let’s break down the two main stages of the initial certification process: the documentation review (Stage 1) and the implementation and effectiveness review (Stage 2).
“
Stage 1 ISO 27001 audit feels like reviewing your business plan with an external auditor, an independent party that checks if your goals and processes make sense on paper. Stage 2 is opening the doors and proving those plans are working in practice to keep the business running smoothly and securely.”
Stage 1 audit
The Stage 1 external audit is primarily a documentation review of your existing policies and procedures against ISO 27001 requirements. The goal is to verify that your documentation is complete and aligned with the ISMS you’ve implemented.
Key documents you must prepare for this step include:
- Statement of Applicability (SoA)
- Scope of the ISMS
- Asset inventory
- Risk assessment methodologies and findings
- Risk treatment plans
- Access control policies
While this stage can extend over a month, the actual audit is shorter. The auditor mainly determines whether your organization is ready to proceed to Stage 2 audit. As part of their findings, the auditor also outlines any areas of non-compliance and recommends corrective action.
Stage 2 audit
This stage is known as the main (or certification) audit, and involves a thorough review of your ISMS. The auditor tests if your security controls are implemented properly, function as per the documentation provided in Stage 1, and are supported by clear ownership.
Stage 2 audit also involves interviews with key stakeholders and leadership to determine whether they understand the ISMS and its function.
Once the auditor completes this assessment, they award you an ISO 27001 certification or issue a report with any minor and major nonconformities you must address, such as:
II. Surveillance audit
Surveillance audits are an essential part of ongoing ISO 27001 compliance. They help maintain audit readiness by operationalizing continuous improvement over reactive compliance.
Once certified, you must bring in an external auditor—most companies choose to use the same auditor—annually to review your ISMS and verify its effectiveness. You will undergo two surveillance audits as part of the standard 3-year ISO certification cycle. During the assessment, the auditor typically:
- Scopes out the areas involved in the assessment
- Reviews remediation efforts
- Checks updates to policies and procedures
- Identifies improvements made to the ISMS (since last audit)
- Assesses management oversight
- If your auditor agrees, surveillance audits can often be performed remotely, this is especially common for technology organisations or cloud-native environments.
“
In addition to being mandatory, another real benefit of ISO 27001 certification is the surveillance audit. It’s your opportunity to confirm with an external party that ISMS is progressing with your business rather than standing still between audits.”
III. Recertification audit
An ISO 27001 certificate is only valid for three years, after which your organization must undergo a recertification audit to renew it. This process is similar to the original certification assessment and designed to confirm that your ISMS meets all current ISO 27001 criteria.
To stay prepared for the recertification audit, monitor your ISMS and conduct internal reviews consistently. Maintain logs of necessary documentation and control updates, including previous audit findings and remedial actions taken. That way, you can minimize the risk of unexpected nonconformities and delays.
{{cta_withimage2="/cta-modules"}} | ISO 27001 compliance checklist
Best practices to prepare for ISO 27001 audits
Here are some of the best practices that will help your organization stay prepared for ISO 27001 audits:
- Carefully define the scope of your ISMS: Scoping your ISMS correctly sets the foundation for successful audits. Set it too broad or narrow, and you risk confusion and delays between Stage 1, Stage 2 and surveillance audits. The best practice is to define it with leadership and technical teams and agree on what systems, locations, and data your ISMS will cover. Then, refine the scope until it’s clear and actionable.
- Document all changes made to your ISMS: Keep up-to-date records of all changes to your ISMS controls, policies, and procedures to demonstrate continuous improvement. Keep these documents in a central repository for ease of access.
- Conduct regular stakeholder training: Regular training and communication campaigns help your stakeholders understand how the ISMS functions and their security responsibilities.
- Monitor your ISMS for effectiveness: Establish monitoring workflows and define KPIs to track the impact of your ISMS. This helps catch inefficiencies early and demonstrate ROI to leadership.
- Engage leadership and key stakeholders: Encourage founder and leadership participation. When leadership is directly involved in setting and reviewing security goals, it signals that ISO 27001 isn’t just a compliance obligation but an integral part of a secure, well-governed business which ultimately builds customer trust.
- Leverage automation: Automation and trust management tools like Vanta can make audit processes consistent with real-time and centralized insights. The best solutions also help with risk management and reduce the manual effort for both ISO 27001 preparation and audits.
Simplify ISO 27001 audits and certification with Vanta
Vanta is a leading agentic trust platform that helps achieve and maintain ISO 27001 certification through clear guidance, documentation, and risk management workflows, among other resources. Organizations using Vanta can reduce the audit prep time by nearly 50% with the help of automated processes and continuous monitoring.
Vanta’s dedicated ISO 27001 product can streamline evidence collection, perform control checks, and automatically generate your Statement of Applicability, linking each control to corresponding tests and documentation. Here’s an overview of its core features:
- 1200+ automated, hourly tests
- Automated evidence collection through 400+ integrations
- Centralized dashboard for continuous oversight
- Built-in training resources
- Checklists and templates for defining ISMS scope and identifying vulnerabilities
If you’re pursuing other frameworks such as SOC 2, ISO 27017, ISO 27018, ISO 42001, or ISO 27701, Vanta can cross-map your controls and reuse evidence to help you achieve compliance faster. You can also use Vanta’s partner network to find reputable auditors tailored to your needs.
Book a custom demo today to see the Vanta platform in action.
{{cta_simple2="/cta-modules"}} | ISO 27001 product page
FAQs
Will the auditor object if I reuse the controls of SOC 2 for ISO 27001?
Your auditor shouldn’t object if you reuse SOC 2 controls for ISO 27001, provided you document how you’ve mapped them between frameworks. SOC 2 and ISO 27001 have a significant overlap when it comes to security practices such as access control, vendor management, and incident response.
How do I choose a certification body?
Choose a certification body that’s accredited and experienced in your industry. Only accredited auditors can issue ISO 27001 certification, while sector expertise allows them to understand your specific risks, systems, and compliance nuances.
What happens if I fail an ISO 27001 audit?
You’ll receive an audit report detailing nonconformities. You must then create and implement a remediation plan. Major nonconformities can prompt the auditor to pause or revoke certification until you’ve resolved them.
How can I simplify ISO 27001 auditing through automation?
Automation solutions can simplify the audit process by uncovering compliance gaps in real time, centralizing documentation, and enhancing project management with bespoke tools, helping you maintain continuous audit readiness.
Preparing for an ISO 27001 audit
ISO 27001 audits: What internal and external audits to prepare for
Preparing for an ISO 27001 audit
ISO 27001 audits: What internal and external audits to prepare for
Download the checklist
Preparing for an ISO 27001 audit
Looking to automate up to 80% of the work for ISO 27001 compliance?
We’ve entered an era of growing cyber risks and regulatory scrutiny, and every business feels the pressure to prove it’s on top of its compliance game. Today, one of the most effective ways to demonstrate control over your information security practices is by aligning with recognized security frameworks such as ISO 27001.
While achieving ISO 27001 certification is a strong competitive differentiator, the process itself is extensive and involves several types of audits, both internal and external. It also entails ongoing efforts to keep your information security management system (ISMS) performing as intended.
To pass these audits successfully, you need thorough preparation and a good understanding of each assessment stage. This guide will help you:
- Learn about different ISO 27001 audits and their purposes
- Anticipate the requirements for each
- Apply best practices for staying audit-ready
What are ISO 27001 audits?
ISO 27001 audits are formal assessments that evaluate how effectively your ISMS meets the requirements of the standard. Their purpose is to verify if your organization has implemented the necessary policies and controls to protect sensitive information, as well as assess and mitigate risks.
To maintain ISO 27001:2022 compliance, you have to undergo several audits during the three-year certification lifecycle, including:
- Internal audits, conducted by your own team or external consultants
- External audits, conducted by an accredited body
“
The stages of the audits can be best seen as proving that security is built into the business, not just bolted on. Each phase adds another layer of confidence that your ISMS isn’t only compliant but also continues to operate as it was designed.”
Consult the table below for a brief overview of all relevant ISO 27001 audit stages:
{{cta_withimage2="/cta-modules"}} | ISO 27001 compliance checklist
All about ISO 27001 internal audits
Regular internal audits are an ongoing ISO 27001 requirement listed in clause 9.2. These audits can be useful for identifying and addressing compliance gaps before the official certification process begins. They involve a structured examination of your ISMS before bringing in an accredited external auditor.
Typically, the ISO 27001 internal audit process involves:
- Conducting risk assessments
- Reviewing ISMS documentation
- Testing controls to verify they meet the intended outcomes
The audit can be conducted by hired external consultants or internal stakeholders. If it’s the latter, they need to remain objective and impartial throughout the review, which means they shouldn't audit areas they’re directly responsible for.
Common gaps and misinterpretations during ISO 27001 internal audits
Many organizations orient their internal audits more toward technical Annex controls, such as firewalls, encryption, and access logs, because they’re easier to measure definitively. This can be an oversight, as some of the most valuable internal findings during an ISO 27001 audit stem from governance, process and clause controls, where the ownership isn’t always clear.
For example, ownership of user offboarding often blurs between IT, HR, and security teams. HR knows when an employee leaves, IT manages system access, and security is responsible for oversight, yet no single team owns the process end-to-end.
For a productive internal audit cycle, make sure that your team reviews both human and procedural elements alongside technical controls.
Another common misinterpretation is that ISO 27001 requires all controls to undergo an internal audit every year. In practice, you only need an internal audit program that ensures all ISMS controls are reviewed over time, typically within the three-year certification cycle.
All about ISO 27001 external audits
To obtain an ISO 27001:2022 certificate, you must undergo an external audit conducted by an accredited certification body. There are various certification bodies (who have been audited against ISO/IEC 17021) you can partner with, depending on your location, including:
- ANSI National Accreditation Board (ANAB) for the U.S.
- Standards Council of Canada (SCC)
- Deutsche Akkreditierungsstelle GmbH (DAkkS) for Germany
- Comité Français d'Accréditation (Cofrac) for France
- Joint Accreditation System of Australia & New Zealand (JASANZ)
- United Kingdom Accreditation Service (UKAS)
- National Standards Authority of Ireland (NSAI)
- Accredia for Italy
ISO 27001 external audits can be split into three main stages:
- Initial certification audit (conducted in two phases)
- Surveillance audit
- Recertification audit
I. Initial certification audit
The Initial certification audit can take anywhere between 3 and 12 months, depending on your organization’s ISMS maturity, documentation quality, and ISO 27001 readiness.
To make the process smoother, set clear expectations with your auditor early on. Organizations often treat ISO 27001 as a box-checking exercise, but the most successful certification cycles come from open communication and a risk-focused approach. Be upfront with your auditor about any gaps in your ISMS and demonstrate how you’re addressing them. Most auditors expect honesty and accountability over surface-level perfection.
For instance, auditors don’t expect a 20-person startup to maintain the same level of documentation as a global enterprise. They'll be more concerned about whether the ISMS is right-sized for the organisation context and genuinely effective in protecting information assets from relevant risks.
Let’s break down the two main stages of the initial certification process: the documentation review (Stage 1) and the implementation and effectiveness review (Stage 2).
“
Stage 1 ISO 27001 audit feels like reviewing your business plan with an external auditor, an independent party that checks if your goals and processes make sense on paper. Stage 2 is opening the doors and proving those plans are working in practice to keep the business running smoothly and securely.”
Stage 1 audit
The Stage 1 external audit is primarily a documentation review of your existing policies and procedures against ISO 27001 requirements. The goal is to verify that your documentation is complete and aligned with the ISMS you’ve implemented.
Key documents you must prepare for this step include:
- Statement of Applicability (SoA)
- Scope of the ISMS
- Asset inventory
- Risk assessment methodologies and findings
- Risk treatment plans
- Access control policies
While this stage can extend over a month, the actual audit is shorter. The auditor mainly determines whether your organization is ready to proceed to Stage 2 audit. As part of their findings, the auditor also outlines any areas of non-compliance and recommends corrective action.
Stage 2 audit
This stage is known as the main (or certification) audit, and involves a thorough review of your ISMS. The auditor tests if your security controls are implemented properly, function as per the documentation provided in Stage 1, and are supported by clear ownership.
Stage 2 audit also involves interviews with key stakeholders and leadership to determine whether they understand the ISMS and its function.
Once the auditor completes this assessment, they award you an ISO 27001 certification or issue a report with any minor and major nonconformities you must address, such as:
II. Surveillance audit
Surveillance audits are an essential part of ongoing ISO 27001 compliance. They help maintain audit readiness by operationalizing continuous improvement over reactive compliance.
Once certified, you must bring in an external auditor—most companies choose to use the same auditor—annually to review your ISMS and verify its effectiveness. You will undergo two surveillance audits as part of the standard 3-year ISO certification cycle. During the assessment, the auditor typically:
- Scopes out the areas involved in the assessment
- Reviews remediation efforts
- Checks updates to policies and procedures
- Identifies improvements made to the ISMS (since last audit)
- Assesses management oversight
- If your auditor agrees, surveillance audits can often be performed remotely, this is especially common for technology organisations or cloud-native environments.
“
In addition to being mandatory, another real benefit of ISO 27001 certification is the surveillance audit. It’s your opportunity to confirm with an external party that ISMS is progressing with your business rather than standing still between audits.”
III. Recertification audit
An ISO 27001 certificate is only valid for three years, after which your organization must undergo a recertification audit to renew it. This process is similar to the original certification assessment and designed to confirm that your ISMS meets all current ISO 27001 criteria.
To stay prepared for the recertification audit, monitor your ISMS and conduct internal reviews consistently. Maintain logs of necessary documentation and control updates, including previous audit findings and remedial actions taken. That way, you can minimize the risk of unexpected nonconformities and delays.
{{cta_withimage2="/cta-modules"}} | ISO 27001 compliance checklist
Best practices to prepare for ISO 27001 audits
Here are some of the best practices that will help your organization stay prepared for ISO 27001 audits:
- Carefully define the scope of your ISMS: Scoping your ISMS correctly sets the foundation for successful audits. Set it too broad or narrow, and you risk confusion and delays between Stage 1, Stage 2 and surveillance audits. The best practice is to define it with leadership and technical teams and agree on what systems, locations, and data your ISMS will cover. Then, refine the scope until it’s clear and actionable.
- Document all changes made to your ISMS: Keep up-to-date records of all changes to your ISMS controls, policies, and procedures to demonstrate continuous improvement. Keep these documents in a central repository for ease of access.
- Conduct regular stakeholder training: Regular training and communication campaigns help your stakeholders understand how the ISMS functions and their security responsibilities.
- Monitor your ISMS for effectiveness: Establish monitoring workflows and define KPIs to track the impact of your ISMS. This helps catch inefficiencies early and demonstrate ROI to leadership.
- Engage leadership and key stakeholders: Encourage founder and leadership participation. When leadership is directly involved in setting and reviewing security goals, it signals that ISO 27001 isn’t just a compliance obligation but an integral part of a secure, well-governed business which ultimately builds customer trust.
- Leverage automation: Automation and trust management tools like Vanta can make audit processes consistent with real-time and centralized insights. The best solutions also help with risk management and reduce the manual effort for both ISO 27001 preparation and audits.
Simplify ISO 27001 audits and certification with Vanta
Vanta is a leading agentic trust platform that helps achieve and maintain ISO 27001 certification through clear guidance, documentation, and risk management workflows, among other resources. Organizations using Vanta can reduce the audit prep time by nearly 50% with the help of automated processes and continuous monitoring.
Vanta’s dedicated ISO 27001 product can streamline evidence collection, perform control checks, and automatically generate your Statement of Applicability, linking each control to corresponding tests and documentation. Here’s an overview of its core features:
- 1200+ automated, hourly tests
- Automated evidence collection through 400+ integrations
- Centralized dashboard for continuous oversight
- Built-in training resources
- Checklists and templates for defining ISMS scope and identifying vulnerabilities
If you’re pursuing other frameworks such as SOC 2, ISO 27017, ISO 27018, ISO 42001, or ISO 27701, Vanta can cross-map your controls and reuse evidence to help you achieve compliance faster. You can also use Vanta’s partner network to find reputable auditors tailored to your needs.
Book a custom demo today to see the Vanta platform in action.
{{cta_simple2="/cta-modules"}} | ISO 27001 product page
FAQs
Will the auditor object if I reuse the controls of SOC 2 for ISO 27001?
Your auditor shouldn’t object if you reuse SOC 2 controls for ISO 27001, provided you document how you’ve mapped them between frameworks. SOC 2 and ISO 27001 have a significant overlap when it comes to security practices such as access control, vendor management, and incident response.
How do I choose a certification body?
Choose a certification body that’s accredited and experienced in your industry. Only accredited auditors can issue ISO 27001 certification, while sector expertise allows them to understand your specific risks, systems, and compliance nuances.
What happens if I fail an ISO 27001 audit?
You’ll receive an audit report detailing nonconformities. You must then create and implement a remediation plan. Major nonconformities can prompt the auditor to pause or revoke certification until you’ve resolved them.
How can I simplify ISO 27001 auditing through automation?
Automation solutions can simplify the audit process by uncovering compliance gaps in real time, centralizing documentation, and enhancing project management with bespoke tools, helping you maintain continuous audit readiness.
Explore more ISO 27001 articles
Introduction to ISO 27001
ISO 27001 requirements
Preparing for an ISO 27001 audit
Streamlining ISO 27001 compliance
Understanding ISO differences
Get started with ISO 27001
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