ISO 27001 vs SOC 2: Choosing the Right Framework

Key Takeaways

Point	Summary
Output difference	ISO 27001 produces a certificate; SOC 2 produces an audit report
Geographic strength	ISO 27001 is stronger in EU/APAC; SOC 2 is more common in North America
Timeline	ISO 27001: 3-4 months; SOC 2: 4.5-6 months (includes observation period)
Control overlap	~70% of controls are shared between frameworks
Best approach	Often both frameworks together for maximum market coverage

Quick Answer: Choose ISO 27001 for EU/APAC enterprise customers and public sector contracts. Choose SOC 2 for North American SaaS buyers who want technical security validation. Consider both frameworks together if you serve customers globally—the ~70% control overlap (typically for SaaS companies) makes the combined path efficient.

Understanding the Fundamental Difference

ISO 27001: A Certificate

ISO 27001 certification demonstrates that your organization has implemented an Information Security Management System (ISMS) that meets the requirements of ISO/IEC 27001:2022. After a successful audit, you receive a certificate from an accredited certification body that remains valid for three years (with annual surveillance audits).

Key characteristics:

• Binary outcome: certified or not certified
• Listed in public certification registries
• Internationally recognized standard
• Emphasis on management system and continuous improvement

SOC 2: A Report

SOC 2 produces an audit report that describes your controls and provides an auditor's opinion on their effectiveness. The report covers a specific time period and provides detailed information about how your organization handles data security.

Key characteristics:

• Detailed attestation report (not a pass/fail certificate)
• Covers a defined audit period
• Strong focus on technical controls
• Particularly relevant for service organizations

Side-by-Side Comparison

Aspect	ISO 27001	SOC 2
Developed by	International Organization for Standardization (ISO)	American Institute of CPAs (AICPA)
Output	Certificate	Attestation report
Validity	3 years (annual surveillance)	Typically annual
Observation period	Not required	Required for Type 2 (3+ months)
Typical timeline	3-4 months	4.5-6 months
Geographic recognition	Global, strongest in EU/APAC	Primarily North America
Standard focus	Management system approach	Trust Services Criteria
Penetration testing	Not explicitly required	Often included in practice
Documentation	More extensive	Moderate

*Timelines vary based on company size, complexity, and initial security readiness.

Geographic Considerations

When ISO 27001 Has More Weight

Market	Why ISO 27001
European Union	Recognized standard for enterprise procurement
UK	Often paired with Cyber Essentials for government work
Germany, France	Strong preference for ISO standards
Asia-Pacific	Default expectation in Japan, Australia, Singapore
Public sector	Government contracts often require ISO
Regulated industries	Financial services, healthcare in EU

When SOC 2 Has More Weight

Market	Why SOC 2
United States	De facto standard for SaaS and cloud services
North American enterprise	Commonly requested in security questionnaires
Tech-savvy buyers	Appreciate detailed technical attestation
Venture-backed startups	Often expected by investors
SaaS-to-SaaS	Standard B2B expectation in tech sector

Framework Structure Comparison

ISO 27001 Structure

ISO 27001:2022 includes:

• Clauses 4-10: Core ISMS requirements (context, leadership, planning, support, operation, evaluation, improvement)
• Annex A: 93 controls across four themes (organizational, people, physical, technological)

The emphasis is on building a management system that identifies risks and implements appropriate controls based on your specific context.

SOC 2 Structure

SOC 2 is organized around five Trust Services Criteria (TSC):

• Security (required)
• Availability (optional)
• Processing Integrity (optional)
• Confidentiality (optional)
• Privacy (optional)

Organizations select which criteria to include based on their services and customer requirements.

The ~70% Control Overlap

Typically for SaaS companies, ISO 27001 and SOC 2 share substantial overlap in the security controls they address:

Control Area	ISO 27001	SOC 2
Access control	✓	✓
Change management	✓	✓
Incident response	✓	✓
Risk management	✓	✓
Vendor management	✓	✓
Encryption	✓	✓
Logging and monitoring	✓	✓
Business continuity	✓	✓
Security awareness	✓	✓

This overlap means that pursuing both frameworks is significantly more efficient than pursuing them independently.

Timeline Comparison

ISO 27001 Timeline (No Observation Period)

Phase	Duration
Implementation	6-8 weeks
Internal audit	1 week
Stage 1 audit	1 week
Stage 2 audit	1-2 weeks
Total	3-4 months

SOC 2 Type 2 Timeline (Observation Period Required)

Phase	Duration
Implementation	4-6 weeks
Observation period	3-6 months
Audit	2-4 weeks
Total	4.5-6 months

*Timelines vary based on company size, complexity, and initial security readiness.

The key difference: SOC 2 Type 2 requires a minimum observation period where controls must be operating. ISO 27001 has no such requirement—you implement, then audit.

Investment Comparison

Both frameworks have similar investment profiles, typically ranging from €10,000 to €50,000 depending on organization size and complexity. The factors that influence cost are similar:

Factor	Impact on Both Frameworks
Organization size	More people = more documentation and audit time
Scope complexity	More systems = more controls to implement
Technical environment	Modern cloud stack vs. legacy systems
Existing security maturity	Better baseline = faster implementation

Combined Efficiency

Pursuing both frameworks together offers meaningful efficiency:

Approach	Relative Effort
ISO 27001 alone	100%
SOC 2 alone	100%
Both together	~130-140% (not 200%)

The shared controls mean you implement once and certify twice.

Making the Decision

Consider ISO 27001 First If:

• Your primary customers are in Europe or Asia-Pacific
• You're pursuing public sector or government contracts
• You need HDS (Health Data Hosting) certification
• Your enterprise customers specifically request ISO 27001
• You want a formal certificate to display

Consider SOC 2 First If:

• Your primary market is North America
• Your customers are SaaS companies or tech-savvy enterprises
• Penetration testing is frequently requested alongside compliance
• You serve as a service provider processing customer data
• Your investors or board expect SOC 2

Consider Both Frameworks If:

• You serve customers globally
• Different customer segments have different requirements
• You want maximum market coverage
• You're building for long-term enterprise sales

Pursuing Both Frameworks

Strategic Sequencing

Many organizations find it efficient to pursue both frameworks with strategic timing:

Option 1: ISO 27001 First

• Achieve ISO 27001 certification (3-4 months)
• Begin SOC 2 observation period immediately after
• Complete SOC 2 Type 2 (~3 months later)
• Total: ~6 months for both

Option 2: Parallel Implementation

• Implement controls for both frameworks simultaneously
• Achieve ISO 27001 first (no observation period)
• Complete SOC 2 Type 2 after observation period
• Total: ~5-6 months for both

Option 3: Add Second Framework Later

• Complete one framework fully
• Add the second framework leveraging existing controls
• Incremental effort: 6-8 weeks for the second framework

Practical Considerations

Consideration	Recommendation
Unified policies	Write policies that satisfy both frameworks
Evidence collection	Set up automation that serves both audits
Documentation	Use a single compliance platform
Audit coordination	Different auditors, but similar evidence

Common Questions

Can ISO 27001 satisfy SOC 2 requirements?

Not directly. While there's significant overlap, they're separate attestations. Customers who request SOC 2 typically want the SOC 2 report specifically. However, having ISO 27001 makes achieving SOC 2 significantly easier.

If I have SOC 2, do I still need ISO 27001?

Depends on your market. If your customers are primarily in North America and satisfied with SOC 2, you may not need ISO 27001. But for EU/APAC expansion or public sector opportunities, ISO 27001 often becomes necessary.

Which is more rigorous?

They're rigorous in different ways. ISO 27001 emphasizes management system maturity and continuous improvement. SOC 2 provides detailed attestation about control effectiveness. Neither is inherently "harder"—they simply have different focuses.

Do auditors for one framework recognize the other?

Auditors are generally aware of both frameworks and understand the overlap. Having one framework in place demonstrates security maturity, which can streamline the audit for the second framework.

The Bastion Approach

We help organizations navigate both frameworks efficiently:

Challenge	Our Approach
Framework selection	Help you understand which framework(s) your market requires
Unified implementation	Build controls that satisfy both frameworks from the start
Efficient documentation	Single set of policies that address both standards
Coordinated audits	Manage the relationship with multiple auditors
Ongoing maintenance	Support for surveillance audits and annual SOC 2 reports

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Not sure which framework is right for your situation? Talk to our team and we'll help you evaluate your options.

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Sources

• ISO/IEC 27001:2022 - Information security management systems standard
• AICPA SOC 2 - Trust Services Criteria
• AICPA Trust Services Criteria - SOC 2 framework details