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ISO 27001 Annex A 5.20 Addressing Information Security Within Supplier Agreements

Last updated Aug 25, 2025

Author: Stuart Barker | ISO 27001 Expert and Thought Leader

Introduction

I am going to show you what ISO 27001 Annex A 5.20 Addressing Information Security Within Supplier Agreements is, what’s new, give you ISO 27001 templates, an ISO 27001 toolkit, show you examples, do a walkthrough and show you how to implement it.

I am Stuart Barker the ISO 27001 Ninja and using over 30 years experience on hundreds of ISO 27001 audits and ISO 27001 certifications I show you exactly what changed in the ISO 27001 update and exactly what you need to do for ISO 27001 certification.

ISO 27001 Addressing Information Security Within Supplier Agreements

ISO 27001 Annex A 5.20 Addressing information security within supplier agreements is an ISO 27001 control that requires an organisation to establish and agree information security requirements with suppliers.

It is about having a legal mechanism in place. A contract or an agreement or terms of business.

Suppliers represent one of your biggest risks as you cannot directly manage them or influence them and it is likely you rely on them, they have your data and provide services that you need to be successful.

Purpose

The purpose of ISO 27001 Annex A 5.20 is a preventive control that ensures you maintain an agreed level of information security in supplier relationships.

Definition

The ISO 27001 standard defines ISO 27001 Annex A 5.20 as:

Relevant information security requirements should be established and agreed with each supplier based on the type of supplier relationship.

ISO 27001:2022 Annex A 5.20 Addressing information security within supplier agreements
ISO 27001 Toolkit

Implementation Guide

We are going to rely on a couple of mechanism to ensure Information Security In Supplier Relationships.

Supplier Agreements / Contracts

The number one recommendation is to seek professional legal counsel for the provision of all contracts. The following is guidance but you should always defer to professional legal counsel. Always. You are not a lawyer. We are not a lawyer.

Our first line of defence and go to is the supplier agreement or supplier contract. At its core it is a legal mechanism that is legally binding and provides the greatest level of overall protection.

  • It sets out what is required, what will be done, who will do it, what happens if things go wrong.
  • What information is to be provided, accessed and the methods of access.
  • Legal, regulatory and contractual requirements. Elements such as intellectual property rights, copyright information, data protection requirements.
  • The controls and levels of controls that are required by both parties to the agreement.
  • Acceptable and unacceptable use of assets.
  • How to grant and remove access
  • Penalties, indemnities and remediation for failings to meet the contract.
  • Contact information
  • Screening requirements for staff were legally enforceable.
  • How evidence and assurance of information security will be provided
  • Rights to audit
  • How to solve problems or conflicts with the contract
  • Appropriate back up, business continuity and disaster recovery
  • The process for change management
  • Physical security as appropriate
  • Information transfer processes
  • Termination clauses and processes
  • Destruction and removal of data processes
  • Handover at the end of the contract

Contracts are kept and recorded in the ISO 27001 Supplier Register. They are reviewed at least annually, based on risk and significant change or event.

Watch the tutorial

In the video ISO 27001 Information Security Within Supplier Agreements Explained – ISO27001:2022 Annex A 5.20 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.

ISO27001 Third Party Supplier Register Template

ISO 27001 Supplier Policy Template

The ultimate ISO 27001 Supplier Register Template.

ISO27001 Third Party Supplier Policy Template

How to comply

To comply with ISO 27001 Annex A 5.20 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
  • Implement an ISO 27001 supplier register
  • Have agreements with all suppliers that cover information security requirements

How to pass the audit

To pass an audit of ISO 27001 Annex A 5.20 you are going to make sure that you have followed the steps above in how to comply.

What the 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 requriements. 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 5.20 are

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 5.20 FAQ

What policies do I need for ISO 27001 Annex A 5.20 Addressing information security within supplier agreements?

For ISO 27001 Annex A 5.20 Addressing information security within supplier agreements you will need the ISO 27001 Supplier Policy

Why is addressing information security within supplier agreements Important?

ISO 27001 Annex A 5.20 Addressing information security within supplier agreements 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.

Will I need legal advice for ISO 27001 Annex A 5.20

Yes. You will need the support of a legal professional.

Are there templates for ISO 27001 Annex A 5.20?

There are templates that support ISO 27001 Annex A 5.20 located in the ISO 27001 Toolkit.

Do I have to satisfy ISO 27001 Annex A 5.20 for ISO 27001 Certification?

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 5.20 Addressing information security within supplier agreements is a fundamental part of your control framework and any management system. It is explicitly required for ISO 27001.

Can I write polices for ISO 27001 Annex A 5.20 myself?

Yes. You can write the policies for ISO 27001 Annex A 5.20 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.

Where can I get templates for ISO 27001 Annex A 5.20?

ISO 27001 templates that support ISO 27001 Annex A 5.20 are located in the ISO 27001 Toolkit.

How hard is ISO 27001 Annex A 5.20?

ISO 27001 Annex A 5.20 is hard. The documentation required is extensive. We would recommend templates to fast track your implementation.

How long will ISO 27001 Annex A 5.20 take me?

ISO 27001 Annex A 5.20 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.

How much will ISO 27001 Annex A 5.20 cost me?

The cost of ISO 27001 Annex A 5.20 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.

ISO 27001 Information Security In Supplier Relationships: Annex A 5.19

ISO 27001 Monitor, Review And Change Management Of Supplier Services: Annex A 5.22

Further Reading

ISO 27001 Supplier Security Policy Beginner’s Guide

ISO 27001 controls and attribute values

Control typeInformation
security properties
Cybersecurity
concepts
Operational
capabilities
Security domains
PreventiveConfidentialityIdentifySupplier relationships securityProtection
IntegrityGovernance and ecosystem
Availability

About the author

Stuart Barker is an information security practitioner of over 30 years. He holds an MSc in Software and Systems Security and an undergraduate degree in Software Engineering. He is an ISO 27001 expert and thought leader holding both ISO 27001 Lead Implementer and ISO 27001 Lead Auditor qualifications. In 2010 he started his first cyber security consulting business that he sold in 2018. He worked for over a decade for GE, leading a data governance team across Europe and since then has gone on to deliver hundreds of client engagements and audits.

He regularly mentors and trains professionals on information security and runs a successful ISO 27001 YouTube channel where he shows people how they can implement ISO 27001 themselves. He is passionate that knowledge should not be hoarded and brought to market the first of its kind online ISO 27001 store for all the tools and templates people need when they want to do it themselves.

In his personal life he is an active and a hobbyist kickboxer.

His specialisms are ISO 27001 and SOC 2 and his niche is start up and early stage business.