ISO 27001 vs SOC 2: Which Framework Do You Need?

"Should we get ISO 27001 or SOC 2?" is the most common question startups ask when enterprise customers start requesting compliance documentation.

The answer depends on your customers, your geography, and your timeline. Here's a practical comparison to help you decide.

Quick Comparison

Dimension	SOC 2	ISO 27001
Governing body	AICPA	ISO/IEC
Geography	Primarily US/Canada	Global
Type	Attestation report by CPA firm	Certification by accredited audit body
Scope	Service-specific	Organization-wide ISMS
Controls	Flexible — you define your own	93 Annex A controls (standardized)
Output	SOC 2 report (restricted/general use)	ISO 27001 certificate
Timeline	3-6 months (Type I), 6-12 months (Type II)	6-12 months for initial certification
Cost	$30,000-100,000+	$10,000-50,000+
Overlap	~70% overlap with ISO 27001	~70% overlap with SOC 2

SOC 2 in Detail

SOC 2 is organized around five Trust Services Categories. Security (Common Criteria) is always required; the others are optional:

Category	When Required
Security (CC)	Always
Availability	SaaS with uptime SLAs
Processing Integrity	Data processing services
Confidentiality	Handling confidential data
Privacy	PII processing

SOC 2 is flexible — you define your own controls and the auditor evaluates whether they meet the Trust Services Criteria. This flexibility is both a strength and a weakness: it means your SOC 2 report is specific to your service but harder to compare across companies.

ISO 27001 in Detail

ISO 27001 requires implementing an Information Security Management System (ISMS) that covers your entire organization. The 93 Annex A controls are standardized, meaning every ISO 27001 certified company is assessed against the same framework.

The certification is issued by an accredited body and is internationally recognized.

Where They Overlap

About 70% of the work transfers between the two frameworks. The Common Criteria (CC1-CC9) in SOC 2 map directly to ISO 27001 controls:

SOC 2 Criteria	ISO 27001 Cross-Reference
CC1 (Control Environment)	A.6.1-A.6.4, Clause 5
CC2 (Communication)	Clause 7, A.5.14, A.6.3
CC3 (Risk Assessment)	Clause 6, Clause 8
CC4 (Monitoring)	Clause 9
CC5 (Control Activities)	A.5.1, A.5.3, A.5.15
CC6 (Logical/Physical Access)	A.5.15-A.5.18, A.7.2, A.8.5, A.8.24
CC7 (System Operations)	A.5.24-A.5.30, A.8.8-A.8.16
CC8 (Change Management)	A.8.9, A.8.25, A.8.32
CC9 (Risk Mitigation)	A.5.19-A.5.22, A.5.30

If you already have one framework in place, adding the second requires roughly 30% additional effort rather than starting from scratch.

How to Decide

Choose SOC 2 first if:

Your customers are primarily US-based enterprises
You're a SaaS company with uptime SLAs
Customers are asking specifically for a "SOC 2 report"
You need the fastest path to a compliance deliverable (Type I can be done in 3 months)

Choose ISO 27001 first if:

You sell internationally (Europe, Asia-Pacific, Middle East)
Customers or RFPs specifically require ISO 27001 certification
You want a standardized, comparable certification
You're in a regulated industry where ISO standards carry weight
You need a framework for building a comprehensive ISMS from scratch

Choose both if:

You sell to both US and international enterprises
Your largest customers require one and your pipeline requires the other
You want to leverage the 70% overlap and get both done efficiently

Cost Considerations

SOC 2 tends to be more expensive overall because the annual audit report itself costs $30,000-100,000+ from a CPA firm, and you need it refreshed annually.

ISO 27001 certification audit costs $10,000-50,000+ but the certificate lasts three years (with annual surveillance audits that are smaller in scope). The upfront investment in building the ISMS is significant, but the ongoing cost is lower.

The internal audit — which is required for ISO 27001 and recommended for SOC 2 readiness — is the same work regardless of which framework you choose.

The Practical Approach

In my experience, the best approach for most startups is:

Build the ISMS — This foundational work supports both frameworks
Get the framework your customers are asking for — Don't guess; ask your sales team what's blocking deals
Add the second framework — Leverage the 70% overlap to get there faster

The worst approach is doing neither and telling prospects "we take security seriously" without any verification.

Ready to start? Book an ISO 27001 internal audit to assess your current controls and identify gaps.