ISO 27001 vs SOC 2: Differences, Cost and Which One You Need

Choose ISO 27001 first if your buyers, tenders or parent company ask for a certificate. Choose SOC 2 first if customers’ security reviews ask for a SOC 2 report.

What ISO 27001 is

ISO 27001 is the international standard for an information security management system (ISMS): the policies, risk process and controls a company uses to manage security, published by ISO and IEC. The current version is ISO/IEC 27001:2022, and its Annex A lists 93 controls in four themes (organizational, people, physical and technological), according to certification body DQS.

ISO calls certification optional, and ISO itself never issues certificates; external certification bodies do. A certificate lasts three years from the certification decision, with surveillance audits at least annually and a recertification audit before it expires, per DQS.

What SOC 2 is

SOC 2 is an examination by a CPA firm of a service organization’s controls relevant to security, availability, processing integrity, confidentiality or privacy, under AICPA standards. The AICPA describes the SOC suite as services that CPAs may provide, so SOC 2 reports come from CPA firms, not from software vendors.

A Type 1 report looks at control design on one date; a Type 2 tests whether the controls worked over a period (which type to get first). The full guide is our SOC 2 certification explainer, and the finance-focused sibling is covered in SOC 1 vs SOC 2 reports.

ISO 27001 vs SOC 2 cost

ISO 27001 and SOC 2 audits cost about the same for a small company: $5,000–$16,000 for an initial ISO 27001 certification audit (Amtivo for under 10 staff, up to Vanta’s estimate) against $12,000–$20,000 for a SOC 2 Type 2 (Drata’s estimate), checked October 24, 2026.

All figures are estimates from compliance software vendors and a certification body, not quotes. Line-by-line budgets, including software list prices, are on our ISO 27001 certification cost and SOC 2 compliance cost pages.

How much do ISO 27001 and SOC 2 overlap?

ISO 27001 and SOC 2 share many control areas, but nobody independent publishes an overlap percentage. Secureframe, a compliance software vendor, claims companies that comply with SOC 2 already meet at least 90% of ISO 27001; treat that as marketing until your own gap analysis says so. The AICPA also sells a mapping of its 2017 Trust Services Criteria to ISO 27001.

What carries over: everyday controls such as access control and incident response, which both frameworks cover. What ISO 27001 adds: a documented ISMS, a risk assessment and risk treatment process, management reviews and a full internal audit cycle, all of which certification body DQS checks before Stage 2. Compliance platforms map one control to both frameworks; see compliance platforms that cover both.

Do you need both, and which comes first?

You need only the one your customers ask for; add the second when a deal requires it. Three rules:

1. Read the security questionnaire. If it asks for a “SOC 2 Type 2 report”, an ISO certificate won’t close it, and the reverse is also true.
2. A customer wants a CPA’s report? Start with SOC 2, the AICPA’s attestation.
3. A tender or overseas buyer wants a certificate? ISO 27001 is an international standard with certificates in 150 countries.

Some audit firms do both. Schellman, for example, is a licensed CPA firm that issues SOC reports and also sells ISO 27001 certification; check any firm’s ISO accreditation in ANAB’s directory before you hire it for both.

How to verify an ISO 27001 certificate or SOC 2 report

You verify an ISO 27001 certificate in IAF CertSearch, the database ISO points to for accredited certifications, or by asking the certification body. In the US, ANAB accredits certification bodies against ISO/IEC 17021-1.

You verify a SOC 2 report by reading it (ask for the full report, not a summary) and checking the CPA firm. The AICPA’s Peer Review Public File lists accounting firms and their peer review enrollment status. Our how we review page explains how we check sources like these.