ISO 27001 vs GDPR
ISO 27001 vs GDPR for SaaS: understand ISMS certification, EU privacy obligations, Annex A and Article 32 overlap, evidence, and sequencing.
Key differences
| Dimension | ISO/IEC 27001 | GDPR |
|---|---|---|
| Legal status | ISO/IEC 27001:2022 is a voluntary certifiable management-system standard used globally. | GDPR is directly applicable EU law with regulator powers and enforceable data-subject rights. |
| Scope boundary | The organization defines and justifies an ISMS scope covering selected locations, processes, technology, and interfaces. | Scope follows processing of personal data, controller or processor roles, establishments, and Article 3 territorial reach. |
| Assessment result | An accredited certification body can issue a three-year certificate subject to surveillance audits. | There is no official GDPR certificate required for general compliance; accountability is demonstrated through ongoing records and conduct. |
| Control selection | Clause 6 risk treatment and the Statement of Applicability justify inclusion, exclusion, and implementation of Annex A controls. | Articles 5, 24, 25, and 32 require appropriate measures based on processing purpose, rights risk, state of the art, and proportionality. |
| Privacy depth | Annex A includes privacy and PII protection at A.5.34, but certification may cover an ISMS narrower than all GDPR processing. | Lawful basis, transparency, rights, minimization, retention, DPIAs, DPO duties, and international transfers are central obligations. |
| Breach handling | A.5.24–A.5.28 cover planning, triage, response, learning, and evidence collection for information-security incidents. | Articles 33–34 impose specific personal-data-breach assessment, documentation, and notification rules, including a 72-hour authority deadline. |
| Accountability audience | Certification bodies audit conformance; customers often use the certificate in security procurement. | Controllers, processors, supervisory authorities, and courts evaluate compliance and responsibility. |
Control overlap
ISO 27001 supplies a strong operating system for part of GDPR accountability. Risk assessment under Clauses 6.1.2–6.1.3, supplier controls A.5.19–A.5.23, access control A.5.15–A.5.18, logging A.8.15, encryption A.8.24, and incident controls A.5.24–A.5.28 can support GDPR Articles 24, 28, 32, and 33. The same risk register, asset inventory, supplier file, access reviews, and incident records can be tagged to both. Certification does not fill privacy-law gaps: teams still need Article 30 processing records, lawful-basis analysis, Articles 12–22 rights procedures, Article 35 DPIAs, notices, retention decisions, and Chapter V transfer mechanisms.
Sequencing advice
For SaaS processing EU personal data, establish the GDPR data inventory, controller/processor roles, DPAs, subprocessor process, rights workflow, and transfer position first because legal applicability does not wait for certification. Then define an ISO 27001 ISMS scope that includes the production service, engineering operations, and people who operate those obligations. Use privacy risks as inputs to the ISMS risk register and map selected Annex A controls to Article 32. Schedule Stage 1 only after the SoA, internal audit, and management review are credible; do not postpone GDPR notices or breach procedures until Stage 2. Maintain one control library but separate certification claims from legal conclusions.