Baseline with ISO 27001
Confirm ISMS scope; 27018 is an annex built on 27001/27002.
October 20, 2025
Practical Guide to ISO 27018
Written by
As organizations move sensitive workloads to the cloud, protecting personal data has become more complex (and more critical). ISO 27018 is the international privacy standard designed specifically for public cloud environments.
It helps both cloud service providers (CSPs) and enterprise customers demonstrate that personally identifiable information (PII) is processed safely, transparently, and lawfully.
What is ISO 27018?
ISO/IEC 27018:2019 is a code of practice that establishes controls for protecting personal data (PII) in public clouds acting as PII processors. It builds on the ISO 27002 security control framework, adding privacy-specific guidance for the cloud context.
ISO 27018 defines principles for:
Consent and Purpose Limitation: PII is used only for agreed purposes.
Transparency: Users know what data is collected and why.
Data Subject Rights: Mechanisms exist for access, correction, and deletion.
Security Safeguards: Encryption, segregation, and access controls for PII.
Accountability: CSPs provide clear evidence of compliance to customers.
In short: ISO 27018 bridges the gap between cloud security and privacy obligations, helping organizations prove they treat customer data responsibly.
Privacy protections for Cloud Services
ISO 27018 addresses a core challenge of cloud computing: delegated processing.
When a business outsources its data to a cloud provider, it still retains legal responsibility for that data under regulations like the GDPR, HIPAA, or CCPA. ISO 27018 helps close the accountability gap by requiring CSPs to implement strong privacy controls that mirror regulatory expectations. The standard strengthens trust through:
- Contractual clarity on PII ownership and processing limits.
- Explicit restrictions on marketing or profiling using customer data.
- Mandatory breach notification procedures.
- Clear data deletion and return processes at contract end.
- Customer visibility into sub-processor use and location of data storage.
Together, these requirements enable enterprises to show auditors and clients that their cloud vendors operate under robust, auditable privacy controls.
Key requirements
ISO 27018 vs ISO 27701
Many cloud providers pursue ISO 27018 + ISO 27701 to cover both processor and controller obligations; a strong signal of trust to customers and regulators.
Steps to certification
- Confirm ISO 27001 foundation: ISO 27018 extends your existing ISMS.
- Identify PII data flows: Map where personal data is stored and processed.
- Perform a gap assessment: Compare current practices against 27018 controls.
- Implement privacy controls: Consent tracking, deletion workflows, data registers.
- Update contracts and SLAs: Reflect privacy commitments and responsibilities.
- Train and test: Educate staff on PII handling; run breach simulations.
- Internal audit and external review: Validate compliance and prepare for certification audit.
Complyance helps cloud-driven enterprises automate privacy audits, map ISO 27018 to ISO 27701 and GDPR, and maintain evidence in real time. Book a Demo to see how your team can simplify cloud privacy compliance.
FAQs
Is ISO 27018 mandatory for cloud providers? No, but it’s a globally recognized benchmark for privacy assurance and a competitive advantage in procurement and vendor reviews.
Can ISO 27018 be certified independently? It’s usually audited as an extension to ISO 27001, but some CBs offer stand-alone attestation.
How does ISO 27018 relate to GDPR? It provides a framework for GDPR Article 28 (Processor Obligations) and other privacy laws worldwide.
What’s the difference between ISO 27018 and CSA STAR? CSA STAR focuses on cloud security maturity; ISO 27018 focuses on data privacy controls within cloud environments.
Complyance is the AI powered, end-to-end GRC platform
