Know the Difference between ISO 27001 vs 27002 vs 27003

Last Updated on August 20, 2024

The ISO 27000 standards seek to cover and support all the most critical aspects of an organization’s information security management system (ISMS) and related activities. The flagship standard in the series—and its primary certifiable standard—is ISO 27001, which specifies all the technical criteria for designing, implementing, and monitoring an ISO-compliant ISMS.

The primary companion standards to ISO 27001 are ISO 27002 and ISO 27003. These complementary guidelines work together to give companies more in-depth direction and background on implementing the ISO 27001 requirements.

This article summarizes, compares, and contrasts ISO 27001 versus 27002 versus 27003. It explains what each standard includes, how they work together, and when to use them.

What is ISO 27001?

ISO 27001 is the international “gold standard” among cybersecurity frameworks. It specifies a set of ISMS best practices, policies, procedures, and technical controls to effectively assess and manage information-related risk.

A key reason why ISO 27001 is so popular is that an organization can be certified compliant by an independent, accredited third party. An ISO 27001 certificate gives customers, investors, regulators, and stakeholders definitive proof and peace of mind that your business can protect sensitive data.

The ISO 27001 framework tells you what requirements and controls your ISMS should include, depending on the scope of your environment and identified risks. However, it does not provide much explanation on how to implement those requirements. ISO 27002 and ISO 27003 each help with “the how” in different ways.

What is ISO 27002?

ISO 27002 provides supporting guidance on how to select, implement, and manage the appropriate ISO 27001 Annex A controls based on your ISMS risk assessment. An organization can also apply ISO 27002 as a foundation for developing its own cybersecurity standards and processes.

Most organizations pursuing ISO 27001 certification should also become familiar with ISO 27002 as the two documents are meant to be used together. ISO 27001 provides only a few sentences per control, while ISO 27002 devotes about a page to each control. The latter explains each control’s objective, how it should work, and how best to implement it based on your risk assessment.

What is ISO 27003?

Like ISO 27002, ISO 27003 offers additional guidance on implementing your ISO 27001 ISMS. Its focus is on helping you develop an ISMS project plan from the ground up. Some of the steps ISO 27003 covers include:

• How to gain senior management’s support for your ISMS
• Defining an ISMS implementation project scope
• Planning an ISMS implementation project

For easy reference, ISO 27003 is organized around Clauses 4 through 10 in ISO 27001. For each clause and subclause, it provides a deeper level of explanation on the requirements, including additional details and supporting examples.

Difference Between ISO 27000 series standards

ISO 27001 vs 27002

ISO 27001 is the certifiable information security standard. ISO 27002 is an indispensable accompanying guide that provides details on ISO 27001 control implementation. There are different versions of ISO 27002 that correspond to the different ISO 27001 versions. For example, ISO 27002:2022 pairs with ISO 27001:2022.

As noted above, ISO 27002 includes more details on the ISO 27001 Annex A controls, including its purpose and objectives, how it is intended to operate, and implementation tips.

Another key difference between ISO 27001 versus ISO 27002 is that the former is a certification standard that describes the full set of potential requirements for ISMS compliance. You cannot be certified against ISO 27002 as it is just a supporting document, not standalone guidance.

ISO 27001 vs 27003

Like ISO 27002, ISO 27003 is an accompanying guide that supports any organization to design, plan, and implement a best-practice ISO 27001 compliant ISMS.

Similar to ISO 27002, ISO 27003 is not a certification standard. Companies seeking ISO 27001 certification are not required to apply or follow ISO 27003. Likewise, ISO 27003 does not cover any requirements or controls beyond what ISO 27001 defines.

ISO 27002 vs 27003

ISO 27002 and ISO 27003 both provide useful supporting guidance for organizations looking to comply with ISO 27001 requirements or undergo an ISO 27001 certification audit.

However, the goals of the respective documents differ:

• ISO 27002 focuses on helping you determine which ISO 27001 recommended controls to implement in your ISMS and how best to implement them
• ISO 27003 focuses on helping you design and plan your ISO 27001 ISMS implementation in alignment with best practices.

An ideal approach is to use ISO 27002 and 27003 together to better understand and implement the applicable ISO 27001 requirements within your ISMS. Organizations can also use the two documents independently.

Other ISO 27000 series standards

While ISO 27001, 27002, and 27003 are better known, there are other international guidance standards in the ISO 27000 series to help optimize information security management and ensure compliance with ISO 27001 requirements. These include:

• ISO 27004, which provides guidance on monitoring, measuring, analyzing, evaluating, and reporting on your ISMS performance and effectiveness. Its goal is to help you identify and improve weak areas in your ISMS.
• ISO 27005, which provides guidance on managing information security risks. Its goal is to help you meet all the ISO 27001 requirements around information security risk management, especially risk assessment and risk treatment.
• ISO 27007, which provides guidance on managing and performing ISMS internal audits. Its goal is to help ensure your internal audit program meets the ISO 27001 requirements. ISO 27007 is also useful for third-party ISO 27001 auditors.

When to use ISO 27001 vs 27002 vs 27003?

When and how you can most effectively use ISO 27001 vs 27002 vs 27003 differs with your business goals and current information security program.

Use ISO 27001:

• As the foundation for your ISMS, based on best-practice risk assessment (identifying and rating applicable risks) and risk treatment (taking agreed steps to address identified risks).
• To certify your ISMS as ISO 27001 compliant and thus demonstrate a robust information security posture to customers and other potentially international stakeholders.
• To help demonstrate compliance with other legislative, regulatory, and/or industry requirements, such as HIPAA or CMMC in the US.

Use ISO 27002:

• To optimize your initial ISMS implementation or make ongoing improvements.
• To help you identify which ISO 27001 recommended controls are applicable to your specific ISMS.
• To support ISO 27001 compliance and certification.

Use ISO 27003:

• To help outline and plan your ISMS implementation project.
• To gain traction with senior leaders and key contributors across your company for your ISO 27001-based information security program.

What’s next?

CBIZ Pivot Point Security has been helping businesses across industries achieve and sustain ISO 27001 certification for over 16 years. With us as your trusted partner, the success of your ISO 27001 certification effort is a guaranteed reality. Our success rate bringing clients to ISO 27001 certification is 100%.

Contact us to speak with an ISO 27001 expert about your information security goals.