In this ultimate how to implement guide to ISO 27001 Annex A 5.19 Information Security in Supplier Relationships, you will learn directly from an ISO 27001 Lead Auditor:
- The requirement of the control
- The required implementation steps
- The minimum requirement
I am Stuart Barker, the ISO 27001 Lead Auditor and author of the Ultimate ISO 27001 Toolkit.
Using over 30 years of industry experience across hundreds of audits, I’m giving you the exact templates, walkthroughs, and practical examples you need to achieve ISO 27001 certification.
Table of contents
- ISO 27001 Annex A 5.19 Information Security in Supplier Relationships Implementation Checklist
- 1. Formalise the Supplier Security Policy
- 2. Categorise and Risk-Assess the Supplier Base
- 3. Conduct Manual Technical Due Diligence
- 4. Embed Security Clauses into Contracts
- 5. Enforce the Right to Audit
- 6. Manage Changes to Supplier Services
- 7. Establish Secure Remote Access Protocols
- 8. Monitor and Review Supplier Service Delivery
- 9. Plan for Secure Decommissioning and Exit
- 10. Address N-th Party (Sub-supplier) Risk
- ISO 27001 Annex A 5.19 SaaS / GRC Platform Implementation Failure Checklist
Implementing ISO 27001 Annex A 5.19 Information Security in Supplier Relationships is a technical mandate to secure supply chain integrity through manual technical due diligence and contractual rigour. This process provides the business benefit of mitigating third-party risks, ensuring data sovereignty and sustained regulatory compliance across the vendor ecosystem.
ISO 27001 Annex A 5.19 Information Security in Supplier Relationships Implementation Checklist
Use this implementation checklist to achieve compliance with ISO 27001 Annex A 5.19. True security in the supply chain is achieved through rigorous technical vetting and physical verification, not by simply collecting SOC2 reports in a GRC dashboard.
1. Formalise the Supplier Security Policy
Control Requirement: A policy must be established to mitigate risks associated with supplier access to the organisation’s assets.
Required Implementation Step: Draft a bespoke Supplier Security Policy that defines minimum technical standards for any third party handling your data. Do not use a generic template; specify encryption requirements, mandatory MFA, and specific notification timeframes for security breaches that align with your internal RTO and RPO.
Minimum Requirement: A board-approved policy document that is referenced in every new supplier contract.
2. Categorise and Risk-Assess the Supplier Base
Control Requirement: All suppliers must be identified and categorised based on the risk they pose to information security.
Required Implementation Step: Build a manual Supplier Register in a controlled document. Categorise suppliers as ‘Critical’, ‘High’, or ‘Standard’ based on their level of access to your production environment or PII, and document the specific risks (e.g., data transit, geographic location) identified for each.
Minimum Requirement: A complete register of all third-party vendors with a documented risk score for each entry.
3. Conduct Manual Technical Due Diligence
Control Requirement: Information security requirements must be agreed upon with the supplier before granting access.
Required Implementation Step: Move beyond automated questionnaires. Schedule a technical call with the supplier’s Lead Engineer to verify their actual implementation of controls, such as their patch management schedule and log retention periods, rather than accepting a ‘Yes’ on a web form.
Minimum Requirement: Records of a technical interview or a signed, detailed security questionnaire verified by your IT lead.
