ISO 27001 Annex A 5.25: Assessment and decision on information security events

What auditors look for

Auditors check that 5.25 is either justified as not applicable in your Statement of Applicability or implemented and working. Typical evidence includes:

• Triage criteria
• Event and incident log
• Records of classification decisions

How to implement 5.25 in practice

1. Use a short decision checklist
2. Record why events were not escalated
3. Escalate when in doubt
4. Name an owner for 5.25, decide how often it runs and file evidence each time, so the control is audit-ready all year.

Recording 5.25 in the Statement of Applicability

List 5.25 with whether it applies, the reason (usually the risks it treats or a legal or contractual requirement), its implementation status and where the evidence lives. If you exclude it, explain why none of your risks or obligations require it.

Free resources

• GDPR data breach log template
• ISO 27001 and GDPR readiness assessment
• 10 steps to implement ISO 27001
• Remote ISO 27001 consultant

More organizational controls

• 5.21 Managing information security in the ICT supply chain
• 5.22 Monitoring, review and change management of supplier services
• 5.23 Information security for use of cloud services
• 5.24 Information security incident management planning and preparation
• 5.26 Response to information security incidents
• 5.27 Learning from information security incidents
• 5.28 Collection of evidence
• 5.29 Information security during disruption