SOC 2 vs ISO 27001: Which Do You Need?
SOC 2 vs ISO 27001 compared: attestation report vs certification, US vs international, flexible criteria vs prescriptive ISMS -- plus when to do both.
The short answer
The SOC 2 vs ISO 27001 decision usually comes down to one thing: your buyers. If your customers are mostly US-based tech and SaaS companies, they will almost always ask for a SOC 2 report. If you sell into Europe, the UK, or large international enterprises, procurement will often ask for ISO/IEC 27001 certification. The two frameworks cover much of the same security ground, so the choice is less about which is “better” and more about which credential unblocks the deals in front of you.
The rest of this post breaks down what actually differs between SOC 2 and ISO 27001, where they overlap, and when doing both makes sense.
Two different things, not two flavors of the same thing
The most important distinction is structural, and it trips up a lot of founders.
SOC 2 is an attestation report. It is produced under the AICPA’s SSAE 18 attestation standard and issued by a licensed CPA firm. The auditor examines your controls against the Trust Services Criteria and issues an opinion on them. There is no pass/fail stamp and no logo you earn — you get a report (often dozens of pages) that you share with customers under NDA. For a deeper primer, see What Is SOC 2?.
ISO 27001 is a certification. ISO/IEC 27001:2022 is an international standard for an Information Security Management System (ISMS). An accredited certification body (a registrar, not a CPA firm) audits you against the standard and, if you pass, issues a certificate valid for three years. That certificate is a public credential you can point customers to.
So the common phrasing “SOC 2 certification” is technically wrong: SOC 2 gives you a report and an opinion, while ISO 27001 gives you a certificate. That difference shapes almost everything downstream.
How the scope is defined
This is the second big split.
SOC 2 is criteria-based and flexible. Security (the Common Criteria) is always in scope. You then choose whether to add any of the four optional Trust Services Criteria — Availability, Processing Integrity, Confidentiality, and Privacy — based on what you actually do and what customers care about. The AICPA tells you what outcomes to meet; you design the specific controls that meet them. See The 5 Trust Services Criteria for how to pick.
ISO 27001 is management-system-based and more prescriptive. You must build a real ISMS: documented scope, a risk assessment and risk treatment methodology, security objectives, management review, internal audits, and continual improvement (Clauses 4-10 of the standard are all mandatory). On top of that, Annex A lists 93 controls across four themes — Organizational, People, Physical, and Technological in the 2022 revision. You document which controls apply in a Statement of Applicability (SoA) and justify any exclusions against your risk assessment.
Put simply: SOC 2 lets you design controls to meet outcomes; ISO 27001 hands you a control catalog and a management framework you must implement and continuously run.
Side-by-side comparison
| Dimension | SOC 2 | ISO/IEC 27001 |
|---|---|---|
| What it is | Attestation report + auditor opinion | Certification against a standard |
| Standard body | AICPA (under SSAE 18) | ISO / IEC (27001:2022) |
| Who audits you | Licensed CPA firm | Accredited certification body |
| Output | Report you share under NDA | Public certificate (valid 3 years) |
| Geographic weight | US-centric, dominant in North America | International, recognized globally |
| Scope model | Choose Trust Services Criteria | Full ISMS + Annex A controls |
| Prescriptiveness | Outcome-based, flexible controls | Prescriptive ISMS + control catalog |
| Point-in-time vs period | Type I (design) or Type II (operating) | Certification + annual surveillance |
| Typical timeline to first credential | ~2-6 months readiness, plus Type II window | ~4-8 months to first certification |
| Renewal | New report each period (often annual) | 3-year cycle: cert + yearly surveillance, recertify in year 3 |
On timing specifically: SOC 2 comes in two forms. Type I attests to control design at a single point in time; Type II attests to operating effectiveness over a period, commonly 3 to 12 months. Most buyers eventually want Type II. See Type I vs Type II and How long SOC 2 takes for the mechanics.
Where they overlap
Here is the good news if you are staring down both: the underlying security work is largely the same. Both frameworks expect you to have real, operating controls for:
- Access control and least privilege (SSO, MFA, provisioning/deprovisioning)
- Risk assessment and risk management
- Vendor and third-party management
- Change management and secure SDLC
- Incident response and monitoring/logging
- Encryption in transit and at rest
- HR security (background checks, onboarding, security training)
- Business continuity and backups
Estimates of control overlap vary, but a large share of your evidence — policies, tickets, access reviews, logs — can satisfy both frameworks. The practical implication: if you build a solid control environment for one, the second is mostly a mapping-and-gap exercise, not a from-scratch rebuild. Tooling that maintains a single set of controls and crosswalks evidence to multiple frameworks is exactly where a platform like avow earns its keep — you collect evidence once and satisfy overlapping requirements across both.
Which buyers ask for which
The framework you need is usually written into someone else’s procurement policy. Rough guide:
- Ask for SOC 2: US SaaS and tech companies, US-based security and vendor-risk teams, mid-market and enterprise buyers in North America. In the US market, SOC 2 is the default expectation for a B2B software vendor.
- Ask for ISO 27001: European and UK enterprises, many APAC buyers, multinational corporations with global procurement standards, and organizations that already run their own ISO-certified management systems and expect the same from vendors.
- Ask for either or both: large global enterprises and regulated industries that accept whichever you have but prefer both, or that explicitly require the one matching their region.
When you are unsure, do the cheap thing first: ask your top prospects and your sales team which credential is showing up in security questionnaires and vendor requirements. Let real demand pick.
Should you do both?
For many early-stage startups, the answer is “one now, the other when a deal requires it.” Doing both at once doubles the readiness effort before you have proof either one is needed.
Do both when:
- You sell meaningfully into both US and international markets.
- Enterprise deals are stalling on the specific credential you lack.
- You are already through one framework and the marginal cost of the second is mostly mapping, not new controls.
Do one when:
- Your customer base is concentrated in a single region.
- You are pre-revenue or early and want the fastest credential that unblocks pipeline.
- Budget and team bandwidth are tight — start where the demand is loudest.
If you do pursue both, sequence them to reuse work. Whichever you complete first becomes the evidence backbone for the second, and the second audit is far shorter because the control environment already exists and operates.
Getting started
Whichever way you lean, the groundwork is nearly identical: define scope, stand up the core controls, and start collecting evidence continuously rather than scrambling before an audit window. The SOC 2 readiness checklist is a good starting map even if ISO is your endpoint, since the control set overlaps so heavily. And if you want a realistic view of investment before you commit, read how much SOC 2 costs — the drivers (scope, auditor, tooling, engineering time) look similar for ISO.
Pick the credential your buyers are actually asking for, build the controls once, and keep the door open to add the second when a deal makes it worth it.