SOC 2 vs ISO 27001: Which Framework Fits Your Business
They are different kinds of thing — an attestation report and a certification against a standard. Which one you need is usually decided by your customers, not by their merits.
GuardsArm Team
Security Experts
The question is usually framed as which is better. It is the wrong question, because they are different kinds of artefact. SOC 2 produces a report an auditor writes about you, containing their opinion and their findings. ISO 27001 produces a certificate stating that your management system conforms to a standard.
And in practice the choice is rarely made on merit — it is made by whichever your customers ask for.
The practical differences
| SOC 2 | ISO 27001 | |
|---|---|---|
| What you get | An auditor's report, typically 40-100 pages | A certificate plus a scope statement |
| Who performs it | A licensed CPA firm | An accredited certification body |
| What is assessed | Controls against Trust Services Criteria | An information security management system |
| Type I / Type II | Type I: design at a point in time. Type II: operating effectiveness over a period | Single model, with surveillance audits |
| Period | Typically 3-12 months observation for Type II | Three-year cycle |
| Flexibility | You select which criteria apply | Annex A controls with a Statement of Applicability |
| Recognised in | Predominantly North America | Internationally |
| Shareable | Under NDA, usually | Certificate is public; the SoA usually is not |
The report-versus-certificate distinction matters more than it sounds. A SOC 2 Type II report lets a customer read what was tested and what exceptions were found. An ISO certificate does not — which is why a diligent reviewer asks for the Statement of Applicability alongside it.
Which to choose
Choose SOC 2 if your buyers are North American, you sell software or a service handling customer data, and procurement is asking for "your SOC 2". Go straight to Type II if you can; Type I is a milestone, not a destination, and most buyers know it.
Choose ISO 27001 if your buyers are European, Asian or governmental, you operate internationally, or you want a framework that structures the whole security programme rather than attesting to a control set.
Do both if you sell into both markets. The overlap is substantial — commonly cited at around 80% of the underlying control work — so the second is far cheaper than the first. Map controls once and evidence once; see compliance automation.
What neither one does
For healthcare organisations in particular:
- Neither discharges HIPAA. The Security Rule applies regardless, and its required risk analysis is a separate obligation with its own expectations.
- Neither proves you are secure. Both assess a managed approach over a defined scope. An organisation can hold both and be breached — several have.
- Neither covers what is out of scope, which is the thing most often misread by whoever receives the certificate.
Treat them as evidence of a managed programme, which is what they are, rather than as a security outcome.
Timeline and cost, compared
Neither is fast, and the gap between them is smaller than usually assumed once the underlying work is counted.
| SOC 2 Type II | ISO 27001 | |
|---|---|---|
| Readiness work | 3-6 months | 6-9 months |
| Observation / operating period | 3-12 months | ~3 months of ISMS records before Stage 2 |
| Audit | Weeks | Two stages, weeks apart |
| Total to first artefact | 9-15 months | 10-15 months |
| Recurring | Annual report | Annual surveillance, recertify at year three |
| Largest cost | Internal effort | Internal effort |
The observation period is the part that cannot be compressed in either. A Type II report covering three months is achievable; one covering a single week is not, and buyers increasingly ask about the period.
Doing the second one
If you already hold one and are adding the other, the incremental work is mostly mapping and evidence, not new controls. Practical sequence:
- Map your existing controls to the second framework's requirements
- Identify the genuine gaps — usually risk assessment formality for SOC 2 holders, and specific technical criteria for ISO holders
- Reuse evidence collection rather than duplicating it
- Align the audit periods so evidence gathering happens once
Where to start
Find out which your customers are actually asking for, and in what form. That single answer determines the framework, the scope and the timeline, and it is cheaper to establish in a phone call than to discover at the end of a certification programme.
GuardsArm advises on framework selection and runs readiness programmes for both. Book a scoping call.
Written by GuardsArm Team
Our team of cybersecurity experts brings decades of combined experience in penetration testing, compliance auditing, and incident response. We're dedicated to helping organizations strengthen their security posture.
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