SOC 2 vs ISO 27001: which to ask a vendor for
Procurement · 6-min read · Assess a vendor → · updated June 2026
Both SOC 2 and ISO 27001 signal a vendor takes security seriously — but they’re different instruments, and knowing which to ask for (and what each does not prove) makes you a sharper buyer.
The core difference
| ISO/IEC 27001 | SOC 2 | |
|---|---|---|
| Type | Certification (pass/fail) | Attestation report (you read it) |
| Who issues it | Accredited certification body | Independent CPA / auditor |
| What it covers | A managed ISMS (Annex A controls) | Trust Services Criteria (security, + optional availability, confidentiality, etc.) |
| Output | A certificate (3-year cycle, surveillance audits) | A report — Type I (point-in-time) or Type II (over a period) |
| Recognition | International | Common in US SaaS |
Which to ask for
- SOC 2 Type II — the most insight into how controls actually operated day-to-day; ask for the report under NDA and check the period and any exceptions.
- ISO 27001 — a recognised, independently-certified security program; ask for the certificate and the Statement of Applicability.
- Both — many mature vendors hold both; if so, great. If you can get only one, SOC 2 Type II tells you the most about operation.
Assess the certification and the software together
The strongest vendor assessment records the certification (self-reported, with scope and expiry) and the independently-verified vulnerability picture of the product — kept separate, never blended.
- Create a free vendor assessment — questionnaire + verified data, side by side.
- Free vendor security questionnaire template — the questions to ask.
Turn this into action. Both signal a mature security program, but they are not the same thing. The practical differences, and which one to request when assessing a vendor.
Assess a vendor — free →Frequently asked questions
What is the difference between SOC 2 and ISO 27001?
ISO/IEC 27001 is an international standard you get certified against — an accredited body audits your Information Security Management System (ISMS) and issues a certificate. SOC 2 is an attestation: an independent auditor (a CPA firm) examines your controls against the Trust Services Criteria and writes a report. ISO 27001 results in a pass/fail certificate; SOC 2 results in a detailed report you read.
Which should I ask a vendor for?
Ask for whichever fits your context: SOC 2 Type II is common for US SaaS and gives you a readable report on how controls operated over a period (usually 6–12 months); ISO 27001 is widely recognised internationally and signals a managed, certified ISMS. Many mature vendors hold both. If you can only get one, SOC 2 Type II tells you the most about day-to-day operation; ISO 27001 tells you the program is independently certified.
What is the difference between SOC 2 Type I and Type II?
Type I assesses whether controls are suitably designed at a single point in time. Type II assesses whether they actually operated effectively over a period — so Type II is the stronger signal. Always check the report’s period and any exceptions noted.
Does SOC 2 or ISO 27001 mean the software has no vulnerabilities?
No. Both attest to security processes and management — neither tells you whether the specific product version you would run has open critical CVEs, is being actively exploited, or is end-of-life. That is independent, software-composition data, which a certification does not provide. Assess both: the certification and the live vulnerability picture.
This guide is a vendor-neutral explainer for orientation only. It is not audit, certification or legal advice; confirm requirements with your auditor or counsel. See our disclaimer.