ISO 27001 Managing Information Security In The ICT Supply Chain
ISO 27001 Annex A 5.21 is managing information security in your IT suppliers and means you need a process to handle information security risks of your third party suppliers, products, systems and services.
Table of contents
- ISO 27001 Managing Information Security In The ICT Supply Chain
- What is ICT?
- What is ISO 27001 Annex A 5.21?
- How to implement ISO 27001 Annex A 5.21
- Watch the ISO 27001 Annex A 5.21 Tutorial
- ISO 27001 Supplier Register Template
- ISO 27001 Supplier Policy Template
- How to comply
- How to pass the audit
- What an auditor will check
- Top 3 Mistakes People Make
- ISO 27001 Annex A 5.21 FAQ
- Related ISO 27001 Controls
- Further Reading
- ISO 27001 controls and attribute values
What is ICT?
ICT, or information and communications technology (or technologies), is the infrastructure and components that enable modern computing.
What is ISO 27001 Annex A 5.21?
ISO 27001 Annex A 5.21 Managing information security in the ICT supply chain is an ISO 27001 control that requires an organisation to manage the risks associated the ICT products and services supply chain.
ISO 27001 Annex A 5.21 Purpose
The purpose of ISO 27001 Annex A 5.21 is a preventive control that ensures you maintain an agreed level of information security in supplier relationships.
ISO 27001 Annex A 5.21 Definition
The ISO 27001 standard defines ISO 27001 Annex A 5.21 as:
Processes and procedures should be defined and implemented to manage the information security risks associated with the ICT products and services supply chain.
ISO 27001:2022 Annex A 5.21 Managing information security in the ICT supply chain
How to implement ISO 27001 Annex A 5.21
We discussed above that ICT means information and communications technology and we would include cloud services in that.
When we implement we are looking to build on existing best practices for information security, project management, quality management and engineering and not to replace those practices.
You are going to have to ensure that:
- you have information security requirements when acquiring products or services
- your suppliers propagate your security requirements through ‘their’ supply chain if they sub contract
- you request, and understand, of product suppliers, what software components they use
- you request and understand product security functions and how to configure it to be secure
- you implement monitoring and validation of security requirements in your suppliers
- you identify and document critical products and services
- critical components and their origin can be traced through the supply chain
- you have assurance products are functioning as expected
- you have assurance products meet required security levels
- you have rules for sharing information including issues and compromises
- you have process for managing component lifecycles, availability and associated security risks
- you have considered alternate suppliers and how to transfer to them if needed
It is always best and goes without saying, or it should, that you will acquire your products and services from reputable sources.
Watch the ISO 27001 Annex A 5.21 Tutorial
In the video ISO 27001 Managing Information Security In The ICT Supply Chain Explained – ISO27001 Annex A 5.21 I show you how to implement it and how to pass the audit.
ISO 27001 Supplier Register Template
The ultimate ISO 27001 Supplier Register Template.
ISO 27001 Supplier Policy Template
The ultimate ISO 27001 Supplier Register Template.
How to comply
To comply with ISO 27001 Annex A 5.21 you are going to implement the ‘how’ to the ‘what’ the control is expecting. In short measure you are going to
- Implement a topic specific policy
- Implement an supplier management process
- Include in your supplier management process supplier acquisition and supplier transfer
- Implement an ISO 27001 supplier register
- Have agreements with all suppliers that cover information security requirements
- Have information security assurances for critical suppliers as a minimum and ideally all relevant suppliers
How to pass the audit
To pass an audit of ISO 27001 Annex A 5.21 Managing information security in the ICT supply chain you are going to make sure that you have followed the steps above in how to comply.
What an auditor will check
The audit is going to check a number of areas. Lets go through the most common
1. That you have a supplier agreements in place
The auditor is going to check that you have agreements in place with suppliers that cover the information security requirements. It will check that those agreements are in date and cover the products and / or services acquired.
2. That you have an ISO 27001 Supplier Register
You will need an ISO 27001 Supplier Register to record and manage your suppliers. Make sure it is up to date and reflects your reality.
3. Documentation
They are going to look at audit trails and all your documentation and see that is classified and labelled. All the documents that you show them, as a minimum if they are confidential should be labelled as such. Is the document up to date. Has it been reviewed in the last 12 months. Does the version control match.
Top 3 Mistakes People Make
The top 3 Mistakes People Make For ISO 27001 Annex A 5.21 are
1. You have no contracts or legal terms with a supplier
Make sure that there is a contract, agreement, terms of business or some legal mechanism for engaging with suppliers and you have a copy, it is in date and covers what you are using.
2. You have no assurance they are doing the right thing for information security
Make sure you have done your security assessment and can place your hands on an in date certificate such as an ISO 27001 Certification for assurance they are doing the right thing. It needs to be in date a cover the products and / or services you have acquired and are using form the supplier.
3. Your document and version control is wrong
Keeping your document version control up to date, making sure that version numbers match where used, having a review evidenced in the last 12 months, having documents that have no comments in are all good practices.
ISO 27001 Annex A 5.21 FAQ
For ISO 27001 Annex A 5.21 Managing information security in the ICT supply chain you will need the ISO 27001 Supplier Policy
ISO 27001 Annex A 5.21 Managing information security in the ICT supply chain is important because suppliers represent the biggest risk to you. If they are not doing the right thing it is your reputation, your finances, your success that is stake. Get supplier management correct and reduce the risk.
Yes. The support of a legal professional is strongly advised.
There are templates that support ISO 27001 Annex A 5.21 located in the ISO 27001 Toolkit.
Yes. Whilst the ISO 27001 Annex A clauses are for consideration to be included in your Statement of Applicability there is no reason we can think of that would allow you to exclude ISO 27001 Annex A 5.21 Managing information security in the ICT supply chain is a fundamental part of your control framework and any management system. It is explicitly required for ISO 27001.
Yes. You can write the policies forISO 27001 Annex A 5.21 yourself. You will need a copy of the standard and approximately 5 days of time to do it. It would be advantageous to have a background in information security management systems.
ISO 27001 templates that support ISO 27001 Annex A 5.21 are located in the ISO 27001 Toolkit.
ISO 27001 Annex A 5.21 is hard. The documentation required is extensive. We would recommend templates to fast track your implementation.
ISO 27001 Annex A 5.21 will take approximately 1 to 3 month to complete if you are starting from nothing and doing a full implementation. With the right risk management approach and an ISO 27001 Toolkit it should take you less than 1 day.
The cost of ISO 27001 Annex A 5.21 will depend how you go about it. If you do it yourself it will be free but will take you about 1 to 3 months so the cost is lost opportunity cost as you tie up resource doing something that can easily be downloaded and managed via risk management.
Related ISO 27001 Controls
ISO 27001 Annex A 5.30 ICT Readiness For Business Continuity
ISO 27001 Annex A 5.20 Addressing Information Security Within Supplier Agreements
Further Reading
The complete guide to ISO/IEC 27002:2022
ISO 27001 controls and attribute values
| Control type | Information security properties | Cybersecurity concepts | Operational capabilities | Security domains |
|---|---|---|---|---|
| Preventive | Confidentiality | Identify | Supplier relationships security | Protection |
| Integrity | Governance and ecosystem | |||
| Availability |
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.