ISO 27001 vs. SOC 2: What's the Difference (and Do You Need Both)?

If you sell software or services to other businesses, you've probably been asked for one of these two: "Are you ISO 27001 certified?" or "Can you send us your SOC 2 report?" They cover similar ground, but they are not the same thing, and treating them as interchangeable causes real problems during due diligence.

ISO 27001 is a certification

ISO/IEC 27001 is an international standard for an Information Security Management System, or ISMS. It defines a set of controls and, more importantly, a management process: risk assessment, treatment plans, internal audits, management review, and continual improvement. An accredited certification body audits your organisation against the standard and, if you pass, issues a certificate valid for three years, with annual surveillance audits in between.

Because it's a certification, the output is binary: you either hold a valid ISO 27001 certificate or you don't. Buyers in Europe, and increasingly in the Middle East and Asia, tend to ask for it by default.

SOC 2 is a report, not a certificate

SOC 2 comes from the AICPA (the American body that governs public accountants) and evaluates your controls against five Trust Services Criteria: security, availability, processing integrity, confidentiality, and privacy. Only security is mandatory; you choose which of the others apply to your service.

Instead of a certificate, an independent CPA firm produces a report. A Type I report assesses whether your controls are suitably designed at a single point in time. A Type II report, the one most buyers actually want, assesses whether those controls operated effectively over a period, typically 3 to 12 months. SOC 2 reports are US market standard, especially for SaaS companies selling to other SaaS companies.

Where they overlap, and where they don't

Both frameworks care about the same underlying things: access control, change management, incident response, vendor management, encryption. If you've built controls for one, most of the work transfers to the other; that's exactly why cross-framework control mapping matters instead of running two disconnected compliance programs side by side.

Where they differ in practice:

• Geography and buyer expectation. ISO 27001 dominates in Europe; SOC 2 dominates in North America. Sell in both markets, and you'll likely be asked for both eventually.
• Format. A certificate is a yes/no signal a procurement team can check quickly. A SOC 2 report is a long document with an auditor's opinion that a security or legal team actually reads.
• Scope flexibility. SOC 2's optional criteria let you tailor scope to what you actually offer. ISO 27001's Statement of Applicability does something similar, but the certification itself is all-or-nothing against the standard.

Do you need both?

If you sell internationally, or if your sales team keeps losing deals to "we need to see a certificate" on one side of the Atlantic and "send us your SOC 2" on the other, the answer is usually yes, eventually. The good news is that a control mapped once against a shared framework, evidence collected once, an internal audit run once, can satisfy both, provided your management system is set up to track more than one standard from day one rather than bolting a second one on later as a separate project.