ISO/IEC 27001:2022 Annex A · Control 5.20

Addressing Information Security Within Supplier Agreements: A Practical Implementation Guide

Translate supplier risk decisions into clear, enforceable contractual obligations.

This control concerns agreeing relevant information security requirements with each supplier based on the relationship and associated risks.

Practical interpretation: Generic confidentiality language rarely covers operational security. Agreements should allocate responsibilities, evidence rights, incident duties, change control and exit requirements.

What should the control achieve?

Contract requirements reflect supplier risk and service.
Responsibilities are unambiguous.
The organization can obtain assurance and incident support.
Security obligations survive relevant changes and termination.

Step-by-step implementation

Start from assessed risk

Translate data, access, criticality, locations and dependencies into requirements.

Use a clause library

Cover baseline themes while allowing tailored schedules for high-risk services.

Allocate responsibilities

Clarify shared controls, customer configurations and subcontractor duties.

Define assurance rights

Specify reports, audit evidence, testing and remediation expectations.

Set incident obligations

Define notification triggers, timelines, cooperation and evidence preservation.

Plan change and exit

Cover material changes, data return, deletion, portability and continuity.

What this could look like in practice

A cloud hosting agreement includes security responsibilities, approved regions, encryption, vulnerability remediation targets, 24-hour incident notification, subcontractor controls, annual assurance and verified deletion at exit.

Activity	Practical implementation	Evidence
Security schedule	Requirements are tailored from the supplier risk assessment.	Executed contract
Incident clause	Notification, contacts and cooperation are explicit.	Incident schedule
Exit clause	Data format, return period and deletion evidence are defined.	Exit provision

Implementation evidence

Security clause library
Risk-to-clause mapping
Executed agreements
Responsibility matrix
Assurance provisions
Incident clauses
Subprocessor terms
Exit requirements

Useful metrics

High-risk contracts with required clauses
Clause deviations awaiting approval
Suppliers missing assurance rights
Contracts reviewed after material change

Common mistakes

Using one template without tailoring.
Accepting vague ‘industry standard’ promises.
Omitting customer responsibilities.
No deadline for incident notification.
No leverage to verify remediation or deletion.

Questions an auditor may ask

How are clauses selected from risk?
Show shared responsibilities in an agreement.
What evidence can you require?
How are deviations approved?

Implementation test: Compare one critical supplier’s risk assessment with its signed agreement and account for every high-risk issue.

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This independent educational guide paraphrases the practical intent of the control and does not replace the official ISO standards, professional advice or an organization-specific risk assessment. It is not affiliated with or endorsed by ISO.

ISO 27001 Annex A 5.20: Addressing Information Security Within Supplier Agreements – Practical Implementation Guide