ISO 27001 vs SOC 2: which does your business need?
ISO 27001 vs SOC 2 compared — certification vs attestation, who audits each, which your buyers ask for, and why many companies end up doing both (and can reuse most of the work).
The Obligara team ·
ISO 27001 and SOC 2 are the two credentials prospects ask for most when they want proof you can be trusted with their data. They overlap heavily, they are both about information security, and they are routinely confused. But they are different kinds of thing — and picking the wrong one first can cost you months.
The short version: ISO 27001 is an international certification; SOC 2 is a US-born attestation report. Which one you need is driven less by the standards themselves and more by who is asking and where they are.
The 20-second answer
If your buyers are in the UK, EU or the rest of the world and want a recognised certificate, start with ISO 27001. If your buyers are US companies whose security teams ask for "your SOC 2 report", start with SOC 2. If you sell into both, you will likely need both — and the second one is far cheaper than the first once you have the evidence.
ISO 27001 vs SOC 2 at a glance
| ISO 27001 | SOC 2 | |
|---|---|---|
| What it is | An international standard you get certified against | An attestation report written by an auditor |
| The deliverable | A certificate (valid 3 years) | A report (Type I at a point in time, Type II over a period) |
| Who audits you | A UKAS-accredited certification body | A licensed CPA firm |
| Framework | Clauses 4–10 + 93 Annex A controls | Five Trust Services Criteria (Security required; the rest optional) |
| Origin / reach | ISO/IEC — global | AICPA — US, but recognised internationally |
| Who typically asks | UK / EU / global enterprise buyers, tenders | US SaaS buyers, procurement, vendor security reviews |
| Ongoing | Surveillance audits years 1 and 2, recert year 3 | A fresh report each year (usually 12-month Type II window) |
What is ISO 27001?
ISO/IEC 27001 is the international standard for an information security management system (ISMS) — a documented, risk-driven system for protecting information. You define a scope, run a risk assessment, decide which of the 93 Annex A controls apply (your Statement of Applicability), implement them, and operate the system. An accredited certification body then audits you and, if you pass, issues a certificate that is recognised worldwide.
It is a certification: a clear pass/fail outcome and a certificate your buyers can verify. See how we run it in our ISO 27001 module, or check where you stand with the free ISO 27001 readiness check.
What is SOC 2?
SOC 2 is not a certification — it is an attestation. A licensed CPA firm examines your controls against the AICPA's Trust Services Criteria and writes a report expressing an opinion. There are two types:
- Type I describes your controls at a single point in time.
- Type II tests whether those controls actually operated effectively over a period — usually 3 to 12 months. Type II is what most buyers want.
There is no certificate and no pass/fail badge; there is a report you share (usually under NDA) with customers who ask. Our SOC 2 module covers the criteria, audit periods and system description, and the free SOC 2 readiness check shows your gaps.
The biggest difference: certification vs attestation
This is the distinction that trips people up. ISO 27001 gives you a certificate — a binary, verifiable credential. SOC 2 gives you a report — a detailed document a customer's security team reads. A certificate is easier to wave at a tender; a report gives a buyer's auditors more detail to chew on. Neither is "better"; they answer different questions.
Which do buyers actually ask for?
In practice, geography decides:
- US buyers — especially US SaaS and tech companies — almost always ask for a SOC 2 report. It is the default expectation in North American vendor security reviews.
- UK and EU buyers, public-sector tenders, and most of the rest of the world ask for ISO 27001. It maps cleanly to procurement frameworks and is a recognised international mark.
If you are a UK or EU company selling mostly at home, ISO 27001 is usually the first move. If you are chasing US logos, SOC 2 comes first.
You can do both — and the overlap is large
Because both are built on the same security fundamentals — access control, change management, risk management, incident response, supplier management, logging — the evidence overlaps enormously. Once you hold one, the second is mostly a mapping exercise, not a rebuild.
We publish the detail in the ISO 27001 → SOC 2 cross-walk: 71 mappings from ISO 27001 Annex A controls to the SOC 2 Trust Services Criteria. In our experience that reuse removes roughly three weeks of duplicate work when you add the second framework — provided your evidence lives in one place rather than in two disconnected tools.
How to decide
- Follow your pipeline. Look at who is actually asking, and what they ask for. Deals stalled on a security review tell you which credential unblocks revenue fastest.
- Weight by geography. US-heavy pipeline → SOC 2. UK / EU / global → ISO 27001.
- Think 18 months out. If both markets are on the roadmap, start with the one your nearest deals need, and choose tooling that lets the second reuse the first's evidence.
- Measure the gap before you commit. A readiness check (ISO 27001 / SOC 2) tells you how far you are from either, in a few minutes and with no account.
Frequently asked questions
Is ISO 27001 or SOC 2 harder to get?
They are comparable in effort for a first-timer. ISO 27001 front-loads more documentation (the ISMS, risk assessment and Statement of Applicability); SOC 2 Type II front-loads a period of operating your controls so the auditor can test them. The heavy lifting — building and evidencing the controls — is much the same.
Can you have both ISO 27001 and SOC 2?
Yes, and many companies do. The security controls behind them overlap heavily, so once you hold one, the second is largely a mapping and gap-filling exercise rather than a fresh build.
Is SOC 2 recognised in the UK and EU?
It is understood and accepted, especially by tech buyers, but ISO 27001 is the more widely requested credential in UK and EU procurement and tenders. If your buyers are European, ISO 27001 usually carries more weight.
How long is each valid?
An ISO 27001 certificate runs on a three-year cycle with annual surveillance audits. A SOC 2 report is a point-in-time (Type I) or period-of-time (Type II) document, so you commission a fresh one each year.
Where Obligara fits
Obligara runs ISO 27001, SOC 2 and eleven other frameworks in one workspace, with a genuine cross-walk between them and one shared evidence store — so the second framework reuses the first's work instead of duplicating it. See the ISO 27001 and SOC 2 modules, or book a 30-minute walkthrough on your own scope.
This article is general guidance, not legal or certification advice. Your certification body or auditor is the authority on what your specific scope requires.