SOC 2 vs ISO 27001 — Which Framework Does Your Business Need?

Two Frameworks, One Goal

If you are a technology company, a managed service provider, or any organisation that handles customer data, you have almost certainly been asked about SOC 2 or ISO 27001. Both frameworks exist to provide assurance to customers, partners, and regulators that your organisation manages information security effectively. But they approach this goal from fundamentally different angles, and the choice between them — or the decision to pursue both — depends on your market, your customers, your regulatory environment, and your organisational maturity.

Understanding the differences is not just an academic exercise. Choosing the wrong framework wastes budget, delays time-to-market for enterprise sales, and may leave you with a credential that your target customers do not recognise or value. Choosing correctly accelerates trust-building, streamlines vendor assessments, and creates a foundation for broader compliance programmes.

What Is SOC 2?

SOC 2 (System and Organisation Controls 2) is a reporting framework developed by the American Institute of Certified Public Accountants (AICPA). It is not a certification — it is an attestation. A licensed CPA firm examines your organisation's controls against the Trust Services Criteria (TSC) and issues a report expressing an opinion on whether those controls are suitably designed (Type I) or both suitably designed and operating effectively over a period of time (Type II).

The five Trust Services Criteria are:

• Security (Common Criteria): Protection of information and systems against unauthorised access, unauthorised disclosure, and damage. This is the only mandatory criterion — every SOC 2 report must include it.
• Availability: Systems and information are available for operation and use as committed or agreed. Relevant for organisations with SLAs or uptime commitments.
• Processing Integrity: System processing is complete, valid, accurate, timely, and authorised. Critical for financial processing, data analytics, and transaction-based services.
• Confidentiality: Information designated as confidential is protected as committed or agreed. Applies to organisations handling trade secrets, intellectual property, or other sensitive business data beyond personal information.
• Privacy: Personal information is collected, used, retained, disclosed, and disposed of in conformity with the entity's privacy notice and AICPA privacy criteria. Relevant for organisations processing personal data.

The SOC 2 report itself is a detailed document — often 80 to 150 pages — that describes the organisation's system, the controls in place, the tests performed by the auditor, and the results of those tests. Type I reports assess control design at a point in time. Type II reports assess both design and operating effectiveness over a period (typically 6 to 12 months) and are significantly more valuable to customers.

What Is ISO 27001?

ISO/IEC 27001 is an international standard published by the International Organisation for Standardisation (ISO) and the International Electrotechnical Commission (IEC). It specifies the requirements for establishing, implementing, maintaining, and continually improving an Information Security Management System (ISMS). Unlike SOC 2, ISO 27001 is a certification — upon successful audit by an accredited certification body, the organisation receives a certificate that is valid for three years, subject to annual surveillance audits.

The standard comprises management system requirements (Clauses 4-10) and Annex A, which contains 93 controls (in the 2022 version) organised into four themes: Organisational, People, Physical, and Technological. The organisation must conduct a risk assessment, determine which Annex A controls are applicable, and document the rationale in a Statement of Applicability (SoA).

ISO 27001 is recognised worldwide. It is the de facto standard for information security in Europe, the Middle East, Asia-Pacific, and increasingly in North America. The certification is issued by accredited certification bodies (such as BSI, DNV, Bureau Veritas, TUV, or Schellman) and is listed in publicly accessible databases.

Head-to-Head Comparison

Dimension	SOC 2	ISO 27001
Governing body	AICPA (United States)	ISO/IEC (International)
Output	Attestation report (opinion letter)	Certificate (3-year validity)
Auditor	Licensed CPA firm	Accredited certification body
Scope	A defined system or service	The ISMS (may cover entire org or specific scope)
Control framework	Trust Services Criteria (flexible)	Annex A (93 controls, prescriptive)
Risk assessment	Not formally required (implied)	Mandatory (Clause 6.1.2)
Geographic recognition	Primarily North America	Global
Report confidentiality	Restricted (shared under NDA)	Certificate is public; audit details are confidential
Renewal cadence	Annual (new report each year)	3-year certificate with annual surveillance
Typical timeline	3-6 months (Type I), 6-12 months (Type II)	6-12 months (initial certification)
Typical cost (SMB)	$30,000 - $80,000 annually	$15,000 - $50,000 for certification + $8,000 - $20,000 annual surveillance

Trust Services Criteria vs Annex A Controls

The SOC 2 Trust Services Criteria are principle-based. They state what must be achieved (for example, "The entity authorises, designs, develops or acquires, configures, documents, tests, approves, and implements changes to infrastructure, data, software, and procedures to meet its objectives") but leave the specific implementation to the organisation. This flexibility is both a strength and a weakness — it allows organisations to tailor controls to their environment, but it also means that two SOC 2 reports for similar companies may describe very different control environments.

ISO 27001's Annex A controls are more prescriptive. Each control has a defined purpose and implementation guidance (detailed in ISO 27002). For example, A.8.9 (Configuration Management) requires that "configurations, including security configurations, of hardware, software, services, and networks shall be established, documented, implemented, monitored, and reviewed." The organisation must either implement the control or justify its exclusion in the Statement of Applicability.

In practice, there is substantial overlap. An organisation with a well-implemented ISO 27001 ISMS will have most of the controls needed for SOC 2. The reverse is also largely true, though ISO 27001 requires more formal management system processes (risk assessment methodology, internal audit programme, management review) that SOC 2 does not explicitly mandate.

Geographic and Industry Considerations

The most significant factor in choosing between SOC 2 and ISO 27001 is often geography and customer expectations:

• North American market: SOC 2 is the dominant framework. Enterprise buyers in the United States and Canada routinely request SOC 2 Type II reports as part of vendor due diligence. Many procurement teams have standardised review processes built around SOC 2 reports. If your primary market is North American enterprises, SOC 2 is typically the first priority.
• European market: ISO 27001 is the expected standard. European enterprises, particularly in regulated industries, view ISO 27001 certification as a baseline requirement. The standard is referenced in several EU regulations, including GDPR (as a demonstration of appropriate technical and organisational measures), NIS2, and DORA. SOC 2 is less well understood in Europe and may not satisfy procurement requirements.
• Asia-Pacific: ISO 27001 dominates. In markets like Japan, South Korea, India, Singapore, and Australia, ISO 27001 certification is widely expected and often required for government contracts.
• Global SaaS companies: If you serve customers worldwide, you will likely need both. SOC 2 for your North American customers and ISO 27001 for everyone else. The good news is that pursuing both is more efficient than it sounds, given the significant overlap.

Industry-specific expectations also matter:

• Financial services: Both frameworks are valued. Banks and financial institutions in the US expect SOC 2. European financial institutions expect ISO 27001. Many now expect both, plus specific requirements from DORA or FFIEC.
• Healthcare: In the US, HITRUST CSF (which incorporates both SOC 2 and ISO 27001 requirements) is increasingly preferred. ISO 27001 alone satisfies many healthcare requirements outside the US.
• Government: US federal agencies have their own frameworks (FedRAMP, NIST 800-53). ISO 27001 is recognised by many non-US governments. SOC 2 has limited relevance in government procurement outside North America.
• Technology/SaaS: SOC 2 Type II is the most commonly requested credential in B2B SaaS sales in North America. ISO 27001 is the equivalent for international sales.

Cost Comparison: Looking Beyond Audit Fees

Direct audit costs are only part of the picture. The total cost of either framework includes preparation, implementation, tooling, and ongoing maintenance:

SOC 2 Total Cost of Ownership (Year 1):

• Readiness assessment and gap remediation: $10,000 - $40,000
• GRC tooling (Vanta, Drata, Secureframe, etc.): $10,000 - $30,000/year
• CPA firm audit fees (Type II): $20,000 - $60,000
• Internal staff time: 200-500 hours
• Estimated Year 1 total: $50,000 - $150,000

ISO 27001 Total Cost of Ownership (Year 1):

• Gap analysis and ISMS implementation: $15,000 - $50,000
• ISMS tooling and documentation platform: $5,000 - $15,000/year
• Certification body fees (Stage 1 + Stage 2): $10,000 - $35,000
• Internal staff time: 300-600 hours
• Estimated Year 1 total: $40,000 - $120,000

In subsequent years, SOC 2 requires a full annual audit (though Type II readiness is easier after Year 1). ISO 27001 requires annual surveillance audits, which are smaller in scope and cost than the initial certification. Over a three-year cycle, the ongoing costs tend to be comparable, with ISO 27001 having a slight edge due to the lighter surveillance audit model.

Can You Do Both?

Yes, and many organisations do. The key is to build one foundational control framework and map it to both standards rather than running two parallel compliance programmes. The most efficient approach is:

• Start with ISO 27001. The formal risk assessment, ISMS structure, and Annex A controls create a comprehensive security foundation. The management system discipline (internal audits, management reviews, continual improvement) benefits the entire organisation.
• Layer SOC 2 on top. Once the ISMS is in place, mapping controls to the Trust Services Criteria is straightforward. Most Annex A controls directly satisfy SOC 2 requirements. The additional work typically involves documenting service-level commitments (for Availability), processing accuracy measures (for Processing Integrity), and privacy practices (if the Privacy criterion is in scope).
• Use a unified control framework. Maintain a single set of controls with mappings to both ISO 27001 Annex A and SOC 2 TSC. GRC platforms like Vanta, Drata, and OneTrust support this multi-framework approach natively.
• Coordinate audit schedules. Align the SOC 2 audit period with the ISO 27001 certification cycle to avoid evidence collection fatigue. Some organisations schedule the SOC 2 audit period to conclude shortly before the ISO 27001 surveillance audit, allowing evidence to be reused.

Organisations that pursue both frameworks simultaneously typically spend 30-40% less than they would pursuing each independently, due to shared controls, shared evidence, and shared internal processes.

Decision Framework: Which Should You Choose?

Use the following decision criteria to determine the right approach for your organisation:

Choose SOC 2 first if:

• Your customers are primarily in the United States or Canada
• You are a SaaS company selling to North American enterprises
• Your sales team is being blocked by vendor security questionnaires requesting SOC 2
• You need a credential quickly (Type I can be achieved in 3-4 months)
• Your organisation is early-stage and you want flexibility in control design

Choose ISO 27001 first if:

• Your customers are primarily in Europe, Middle East, or Asia-Pacific
• You operate in an EU-regulated industry (NIS2, DORA, GDPR alignment)
• You want a globally recognised certification that opens international markets
• Your organisation values a structured management system approach with formal risk assessment
• You plan to integrate with other ISO standards (ISO 9001, ISO 22301, ISO 42001)

Pursue both if:

• You serve customers globally, including both North American and international enterprises
• Your competitive landscape requires maximum security credentialing
• You are in a highly regulated industry where multiple assurance frameworks are expected
• You are scaling rapidly and want to eliminate security as a barrier to entering any market

Common Misconceptions

• "SOC 2 is easier than ISO 27001." This is not consistently true. SOC 2 Type II requires demonstrating operating effectiveness over time, which demands sustained discipline. ISO 27001 has a more structured approach that some organisations find easier to implement systematically. The difficulty depends on your starting point and organisational culture.
• "ISO 27001 is just a checkbox exercise." Poorly implemented, it can be. But the standard's requirements for risk-based thinking, management commitment, internal audit, and continual improvement are designed to prevent this. Auditors from reputable certification bodies will challenge superficial implementations.
• "SOC 2 reports are pass/fail." They are not. SOC 2 reports contain a qualified or unqualified opinion, plus detailed descriptions of exceptions (control failures) found during the audit. Customers read the details, not just the opinion. A report with numerous exceptions, even with an unqualified opinion on the overall system, can damage trust.
• "You need ISO 27001 before SOC 2." You do not. Many organisations achieve SOC 2 first. However, starting with ISO 27001 provides a stronger foundation for long-term compliance maturity.
• "Once certified, you are done." Both frameworks require ongoing effort. SOC 2 requires annual audits. ISO 27001 requires annual surveillance and a full recertification every three years. The management system must be actively maintained and improved.

How BALTUM Supports Your Decision

BALTUM's consultants work with organisations at every stage of their compliance journey. Whether you are deciding between SOC 2 and ISO 27001, pursuing one or both, or integrating these frameworks with additional standards, our services include:

• Framework Selection Advisory: A structured assessment of your market, customer base, regulatory environment, and organisational maturity to recommend the optimal compliance strategy.
• Gap Analysis: Comprehensive evaluation of your current security controls against your target framework(s), delivered as a prioritised remediation roadmap with effort and cost estimates.
• ISO 27001 Certification Support: End-to-end guidance from ISMS design through successful certification, including risk assessment, SoA development, policy creation, and pre-certification audits.
• SOC 2 Readiness Programme: Preparation for SOC 2 Type I or Type II attestation, including control design, evidence collection processes, and CPA firm coordination.
• Dual-Framework Implementation: For organisations pursuing both SOC 2 and ISO 27001, we design unified control frameworks that satisfy both standards efficiently, minimising duplication and maximising audit readiness.

The choice between SOC 2 and ISO 27001 is not about which framework is objectively better — it is about which framework (or combination) best serves your business objectives, your customers' expectations, and your long-term compliance strategy. The right decision, made early and executed well, pays dividends for years.