SOC 2 vs ISO/IEC 27001: What Each One Actually Proves

Security questionnaires often ask, “Do you have SOC 2 or ISO 27001?” as if the two were interchangeable. They are not. Both are respected forms of security assurance, and their control sets overlap substantially. But they answer different questions, are produced by different kinds of assessor, and give the reader very different documents.

The one-sentence difference

• ISO/IEC 27001 is a certification. An accredited certification body confirms that your information security management system conforms to the standard, within a defined scope.
• SOC 2 is an attestation. A licensed CPA firm gives an opinion on whether your controls meet the AICPA Trust Services Criteria. A Type 2 report also covers whether they operated effectively over a period.

Side by side

What is each one good at proving?

ISO/IEC 27001 is strongest at showing governance. Leadership has defined scope and policy, risks are assessed and treated consistently, and the system is audited internally and reviewed by management. It tells a buyer that security is managed.

SOC 2 is strongest at showing operation. A Type 2 report shows how specific controls were tested across a period and what exceptions were found. It tells a buyer what was done, with enough detail for the buyer’s own risk team or auditors to rely on it.

Where do they overlap?

Both expect a risk assessment, access control, change management, logging and monitoring, incident response, vendor management, security awareness and business continuity. A single, well-designed control set can produce evidence for both, and many organisations map controls once and test them for both programmes.

Where do people get caught out?

1. Scope mismatch. An ISO certificate covering the head office doesn’t help a customer asking about your production SaaS platform. A SOC 2 that carves out your cloud provider leaves the customer to review that provider separately.
2. “Passing” SOC 2. There is no pass mark, so read the exceptions and the complementary user entity controls.
3. Annex A as a checklist. ISO auditors look for risk-based selection, justified in the Statement of Applicability.
4. Evidence produced only for the audit. Both programmes work best when evidence is a by-product of normal operations.

Which do you need?

Start from your customers and markets:

• Selling mainly to North American enterprises? Expect requests for a SOC 2 Type 2.
• Selling internationally, or to buyers who reference ISO in procurement? ISO/IEC 27001 is often expected.
• Selling to both? Plan a combined programme: one control framework, mapped to both, with coordinated audit calendars.

Neither replaces sector-specific requirements such as PCI DSS for card data, HIPAA for US health information or FedRAMP for US federal cloud services.

Further reading in the Academy

See the full guides to ISO/IEC 27001 and SOC 2 for structure, lifecycle and evidence detail.