A Guide for Tech Startups to ISO 27001 Clause 5.3: Organisational Roles, Responsibilities and Authorities

For a growing tech startup, the journey to ISO 27001 certification often feels like a series of complex bureaucratic hurdles. However, ISO 27001 Clause 5.3, which dictates organisational roles, responsibilities and authorities, is much more than a compliance box to tick. It is a foundational element for building a secure, scalable and trustworthy business.

The core challenge in a fast-moving startup environment is ambiguity. Without clear lines of ownership, critical security responsibilities can “fall through the cracks.” This leads to dangerous control gaps, confusion during incident response, or a failure to manage risk effectively. When everyone thinks someone else is responsible, usually no one is.

This High Table guide breaks down ISO 27001 Clause 5.3 into actionable steps specifically for startups. We define what the clause requires, who needs to do what, and how to establish an accountability blueprint to pass your audit and scale securely.

What is ISO 27001 Clause 5.3? (The Plain English Version)

To achieve compliance, you must first understand the core purpose of Clause 5.3: preventing ambiguity to ensure accountability within your Information Security Management System (ISMS). It ensures that everyone knows their duties, possesses the authority to execute them, and keeps leadership informed.

The official standard defines Clause 5.3 as follows:

Top management shall ensure that the responsibilities and authorities for roles relevant to information security are assigned and communicated within the organisation. Top management shall assign the responsibility and authority for: a) ensuring that the information security management system conforms to the requirements of this document b) reporting on the performance of the information security management system to top management.

For a startup, this formal language translates into three straightforward actions for top management:

1. Assign Ownership: Give a specific person or team the job of managing and owning the ISMS.
2. Grant Authority: Ensure that person has the power to execute duties and make necessary decisions.
3. Establish Reporting: Make sure that person reports back to leadership on the effectiveness of the ISMS.

The 3 Non-Negotiables of Clause 5.3

To satisfy an auditor, your startup must adhere to these three principles:

• Mandatory Requirement: This is not optional. You must clearly define and assign roles for your ISMS to be compliant.
• Key Roles: You are required to assign specific responsibilities, including a designated Information Security Manager and a Management Review Team.
• Documentation is Crucial: You must document all assigned roles, responsibilities and authorities. Auditors will verify this documentation to confirm your structure.

Why Clause 5.3 is a Strategic Advantage for Startups

Implementing Clause 5.3 properly does more than help you pass an ISO 27001 audit. It transforms security from an afterthought into a strategic business enabler. This structured approach builds a foundation for sustainable growth and customer trust.

Getting this right delivers four immediate wins:

• Improved Security: Assigning clear owners ensures security tasks are managed by competent people, creating a robust security posture.
• Reduced Risk: A well-defined structure eliminates confusion, significantly reducing the risk of incidents caused by human error or oversight.
• Improved Compliance: Many regulations beyond ISO 27001 require formally documented roles assigned to competent individuals.
• Reputation Protection: In the event of an incident, demonstrating a clear management structure can prevent a manageable event from becoming a company-ending crisis.

The Core Roles Your Startup Needs

In a startup, resources are limited. It is common—and acceptable under ISO 27001—for one person to wear multiple hats. As noted in the guidance, “In a small organisation it may well be the case that one individual is assigned more than one role.”

The focus should be on the function, not the job title. Here are the three core functions you must cover.

The CEO (or Founder)

• Sets the strategic direction for information security.
• Promotes a culture of security aligned with business objectives.
• Signs off on resources, objectives, risks and risk treatment plans.

The Information Security Manager

• Manages the day-to-day operation of the ISMS.
• Owns and continuously improves ISMS documentation.
• Manages the internal audit programme and reports results to management.
• Provides security training and awareness to staff.
• Handles third-party security questionnaires and supplier due diligence.
• Maintains the central log of security incidents.

The Management Review Team

• Signs off on ISMS policies and documents.
• Oversees the risk management process and the company risk register.
• Agrees on or escalates risk mitigation actions.
• Ensures resources are available for risk treatment.
• Communicates security priorities to the wider organisation.

High Table Tip: Do not create new job postings if you don’t need to. Map these functions to your existing team. Your CTO is often the best fit for the Information Security Manager role initially.

Step-by-Step Implementation Guide

You can implement Clause 5.3 in a focused 90-minute session by following this plan:

1. Identify Required Roles: Determine what tasks are needed to run your ISMS effectively and define the roles required to support them.
2. Document Responsibilities: Create a document listing each role and detailing its specific responsibilities to ensure audit clarity.
3. Assign Personnel: Assign these roles to individuals. You can use external resources, internal appointments, or train existing team members.
4. Nominate an Information Security Manager: Formally nominate one person to be responsible for the daily operation of the ISMS.
5. Form a Management Review Team: Assemble a team including representatives from in-scope areas and at least one senior leader for authority.
6. Create a Record of Assignment: Use a matrix or table to formally record who is assigned to which role.
7. Manage and Document Competence: Use a competence matrix to record skills, experience and certifications. This proves to auditors that your team is capable of performing their duties.

Consultant’s Tip: Start with a simple spreadsheet for your assignments. As you scale, move to a formal RACI chart (Responsible, Accountable, Consulted, Informed) to define decision-making powers clearly.

---

---

How to Pass the Audit: What Auditors Look For

To pass the audit for Clause 5.3, you must provide tangible evidence that your roles and responsibilities are not just documented, but functioning in practice.

The Auditor’s Checklist

Be prepared to provide evidence for these three specific areas:

• Documented Roles: The auditor will request a clear document defining roles, specifically looking for the Information Security Manager and Management Review Team.
• Current Personnel: Ensure your documentation is up to date. The people listed in your documents must currently hold those roles and be employed by the company.
• Competence Evidence: You must prove the assigned people are competent. Auditors will review your competence matrix, training records, or conduct interviews to verify this.

Pre-Audit Check: Randomly ask a member of your Management Review Team to explain their role in the ISMS. If they can answer confidently, your system is working.

Common Questions (FAQ) regarding Clause 5.3

Can one person hold more than one role in a startup?

Yes. ISO 27001 is flexible for organisations of all sizes. In smaller companies, one person often holds multiple roles. The critical factor is defining responsibilities clearly and ensuring no conflicts of interest exist (Segregation of Duties).

Do we need to hire new staff or create new job titles?

No. The standard focuses on accountability, not headcount. Responsibilities can be assigned to existing employees, such as an IT manager or co-founder, as an addition to their current role.

What is the difference between roles, responsibilities and authorities?

• Roles: The position or function (e.g., Information Security Manager).
• Responsibilities: The specific tasks associated with the role (e.g., conducting risk assessments).
• Authorities: The power to make decisions (e.g., approving a security policy).

How should we document these roles?

Effective methods include organisational charts, updated job descriptions, a Responsibility Assignment Matrix (RACI chart), or a dedicated section within your Information Security Policy.

Conclusion: Your Foundation for Secure Growth

Properly implementing ISO 27001 Clause 5.3 is a strategic investment. By defining clear roles, responsibilities and authorities, you build a genuine system of accountability. This clarity allows you to scale confidently, pass due diligence with enterprise clients, and build a company that is secure by design.

About the author

Stuart Barker is a veteran practitioner with over 30 years of experience in systems security and risk management.

Holding an MSc in Software and Systems Security, Stuart combines academic rigor with extensive operational experience. His background includes over a decade leading Data Governance for General Electric (GE) across Europe, as well as founding and exiting a successful cyber security consultancy.

As a qualified ISO 27001 Lead Auditor and Lead Implementer, Stuart possesses distinct insight into the specific evidence standards required by certification bodies. He has successfully guided hundreds of organizations – from high-growth technology startups to enterprise financial institutions – through the audit lifecycle.

His toolkits represents the distillation of that field experience into a standardised framework. They move beyond theoretical compliance, providing a pragmatic, auditor-verified methodology designed to satisfy ISO/IEC 27001:2022 while minimising operational friction.