Short answer
ISO 27001 certifies an information security management system against an international standard and produces a public certificate valid for three years. SOC 2 is an attestation report from a licensed CPA firm on controls against the AICPA Trust Services Criteria. Buyers in North America usually ask for SOC 2; elsewhere ISO 27001 is more common.
Key takeaways
- ISO 27001 is a certification; SOC 2 is an attestation report, not a certificate.
- Accredited certification bodies issue ISO 27001; only licensed CPA firms issue SOC 2.
- Most controls overlap, so one control set and one evidence vault can support both.
- Pick by where your customers are and what their security reviews ask for.
The short version
ISO/IEC 27001 asks whether you run an information security management system (ISMS): a governed cycle of risk assessment, controls, internal audit and management review. SOC 2 asks whether the controls behind a service you provide are designed and, for a Type II report, operating effectively over a period. Both are voluntary. Both end with an independent third party looking at your evidence. They answer slightly different questions for slightly different audiences.
| ISO 27001 | SOC 2 | |
|---|---|---|
| What it is | International management-system standard | Attestation report on controls (AICPA) |
| Who issues it | Accredited certification body | Licensed CPA firm |
| What you get | Public certificate | Restricted-use report, Type I or Type II |
| Validity | 3 years, with annual surveillance audits | Covers a set period; usually renewed yearly |
| Scope | The ISMS plus Annex A controls chosen by risk | Trust Services Criteria for the categories you select |
| Where buyers ask for it | Worldwide; strongest in Europe, the Middle East and Asia | Mostly North America |
What each one actually tests
An ISO 27001 audit tests the management system first. Auditors check that clauses 4 to 10 operate: scope, leadership, risk assessment and treatment, the Statement of Applicability, internal audit, management review and corrective action. Annex A controls are then sampled according to what your risk assessment selected. A Stage 1 audit reviews design and documents; a Stage 2 audit tests operation.
A SOC 2 examination tests controls against the criteria. The common criteria (CC1 to CC9) cover security and are always in scope. Availability, processing integrity, confidentiality and privacy are optional categories. A Type I report gives an opinion on design at a date. A Type II report also tests operating effectiveness over an observation period, typically 3 to 12 months, and lists every exception the auditor found.
Neither one is a law. Contracts, procurement questionnaires and regulators' expectations are what make them feel mandatory.
Where they overlap
Most of the day-to-day control work is the same. Access reviews, MFA, vulnerability management, logging, incident response, backup, vendor management and change management appear in both. That means one tested control can produce evidence for both audits if the evidence is collected with both in mind.
A.5.15Access controlCC6.1Logical access securityA.5.18Access rightsCC6.2–CC6.3Provisioning and least privilegeA.8.8Technical vulnerabilitiesCC7.1Detecting vulnerabilitiesA.8.15LoggingCC7.2Monitoring for anomaliesA.5.24–A.5.26Incident managementCC7.3–CC7.5Evaluating and responding to incidentsA.5.19–A.5.22Supplier securityCC9.2Vendor riskA.8.13Information backupA1.2Backup and recovery
Where they differ in practice
- Evidence windows: SOC 2 Type II samples across the whole observation period, so a control that lapsed for two months shows up as an exception. ISO 27001 samples at audit time but expects records that show the control ran.
- Management system: ISO 27001 requires internal audit, management review and documented risk treatment. SOC 2 has no equivalent clause-level structure, though CC3 and CC4 cover risk assessment and monitoring.
- Scope wording: ISO 27001 scope is an organisational boundary. SOC 2 scope is a system description of the services, infrastructure, people and data behind them.
- Output: an ISO 27001 certificate can be shown to anyone. A SOC 2 report is restricted to customers and prospects under NDA, and it shows the exceptions.
Which one first?
Start with what your buyers ask for. If your pipeline is mostly North American SaaS buyers, a SOC 2 Type II usually unblocks deals faster. If you sell into Europe, the Middle East, India or government supply chains, ISO 27001 is the more common request. If you need both, build the ISMS first: its risk assessment and control set make the SOC 2 readiness work shorter, and the reverse is less true.
Checklist
Running both without double work
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Frequently asked questions
Is SOC 2 a certification like ISO 27001?
No. ISO 27001 results in a certificate from an accredited certification body. SOC 2 results in an attestation report in which a licensed CPA firm gives an opinion on your controls.
Can one audit cover both ISO 27001 and SOC 2?
No single audit issues both, but the same controls and evidence can support both. Many organisations align timing so one evidence set answers both auditors.
Which is harder, ISO 27001 or SOC 2?
They are hard in different ways. ISO 27001 adds management-system work such as internal audit and management review; a SOC 2 Type II requires controls to run without gaps across the whole observation period.