If your business handles personal data and cares about security, you'll run into both GDPR and ISO 27001 sooner or later. They're often mentioned in the same breath, which leads to a common misconception that doing one means you've done the other. That's not quite right. This guide explains how the two relate, where they genuinely overlap, and where each goes somewhere the other doesn't.
The fundamental difference
GDPR is law. It's a regulation that applies to any organisation handling the personal data of people in the UK and EU, and non-compliance carries real financial penalties. ISO 27001 is a voluntary international standard for managing information security that you choose to adopt and can be certified against. One is an obligation you can't opt out of; the other is a framework you elect to follow. That distinction shapes everything else.
Where they overlap
The overlap is substantial, because good information security is a core part of protecting personal data. GDPR requires appropriate technical and organisational measures to keep personal data secure, and ISO 27001 is essentially a structured way of delivering exactly those measures. Access control, encryption, risk assessment, incident response, staff awareness and supplier management all serve both. If you implement ISO 27001 well, you're satisfying a large part of GDPR's security expectations almost as a by-product.
Where GDPR goes further
GDPR covers ground that ISO 27001 doesn't touch. It grants individuals specific rights — access, erasure, rectification, portability — that you must be able to honour. It requires a lawful basis for processing, rules around consent, data protection impact assessments, breach notification within strict timeframes, and in some cases a Data Protection Officer. These are legal and privacy obligations, not security controls, so certifying to ISO 27001 alone will never make you GDPR compliant.
Where ISO 27001 goes further
Conversely, ISO 27001 addresses information security far beyond personal data. It covers the confidentiality, integrity and availability of all your information assets — intellectual property, financial records, operational systems — not just data about people. Its formal management system, with defined risk treatment, internal audits and management review, is also more rigorous and auditable than anything GDPR prescribes.
Tackling both together with SnapGRC
Because the two share so much common ground, the smart approach is to manage them from a single control set rather than running two parallel projects. SnapGRC lets you map one set of controls across multiple obligations, so the security work you do for ISO 27001 is visibly credited toward your GDPR security requirements — and you maintain one source of truth for evidence rather than duplicating effort. That's how small teams stay compliant with both without doubling their workload.
