SOC 2 vs ISO 27001: what suits you?

You are building a SaaS product. Clients ask for “security certification.” One asks for ISO 27001 (the international standard from ISO ), another for SOC 2 (the US standard from the AICPA ). What is the difference? Do you need both? This article explains it.

The short answer: 80% of the controls are the same. The difference lies in geography (ISO = Europe, SOC 2 = US), format (certificate vs report) and cost structure. NOREA  (the Dutch professional body for IT auditors) can help you make the choice. Many companies with international ambitions end up choosing both.

The 12 main differences between SOC 2 and ISO 27001

What is SOC 2?

SOC 2 is the American standard for service organisations that process customer data. Developed by the AICPA, aimed at SaaS, cloud providers and data centres.

Core concept: Trust Services Criteria You choose from five categories (Security is mandatory, the rest is optional):

• Security (preventing unauthorised access)
• Availability (keeping systems available)
• Processing Integrity (processing data correctly)
• Confidentiality (protecting confidential information)
• Privacy (handling personal data correctly)

Type I vs Type II:

• Type I: point in time (controls designed on date X)
• Type II: operational effectiveness (controls worked for 3-12 months)

Result: An attestation report of 50-150 pages. You only share this with clients who ask for it (under NDA). No public certificate, no logo.

Re-audit: Full every year. Your report is valid for the period that was audited. After 12 months, your client wants a new report.

Read more about SOC 2

What is ISO 27001?

ISO 27001 is the international standard for Information Security Management Systems (ISMS). Developed by ISO/IEC, recognised in 170+ countries, for all industries.

Core concept: ISMS = management system You build a system to manage information security:

• Policies and procedures
• Risk assessment and treatment
• Controls from Annex A (93 controls, you choose which are relevant)
• Continuous improvement (PDCA cycle)

Structure: 10 chapters (ISO 27001) plus Annex A with controls. You must implement all chapters, but you may exclude controls from Annex A with a reason (Statement of Applicability).

Result: A certificate that is valid for 3 years. You may use the ISO 27001 logo, put it on your website and use it in marketing. Publicly verifiable.

Re-audit:

• Year 1: initial certification audit
• Years 2 and 3: surveillance audits (lighter, checking that your system still works)
• Year 4: recertification (full audit again)

Read more about ISO 27001

The main differences

1. Geographic preference

SOC 2: American DNA

• Developed for the US market
• American enterprises recognise and trust it
• RFPs in the US almost always ask for SOC 2, rarely for ISO 27001
• EU companies wanting to enter the US: SOC 2 is your entry ticket

ISO 27001: European/international

• Recognised in 170+ countries
• EU tenders and public contracts: often require ISO 27001
• Asia, Middle East, Latin America: ISO 27001 is the norm
• Multinationals outside the US: ISO 27001 is familiar

In practice: A Dutch SaaS start-up wants the Netherlands and the US: start with ISO 27001 (local), add SOC 2 once American prospects ask for it. An American SaaS company wants Europe: start with SOC 2, add ISO 27001 once you are growing seriously in the EU.

2. Certificate vs report

SOC 2: confidential report You receive a PDF report. It contains details about your architecture, controls and findings. You only share it with clients who ask for it, under NDA. You may NOT say “we are SOC 2 certified” (because it is not a certificate). You say “we have a SOC 2 Type II report.”

No logo, no public badge. Some vendors do make badges (“SOC 2 Compliant”), but officially this does not exist.

ISO 27001: public certificate You receive a certificate with a number, validity date and scope. This is publicly verifiable on the website of your certification body. You may use the ISO 27001 logo in marketing, on your website and in proposals.

You can proudly say: “We are ISO 27001 certified.”

Marketing impact: ISO 27001 is better for marketing and PR. SOC 2 is better for deal-specific compliance questions. Both have value, but different use cases.

3. Scope flexibility

SOC 2: you choose your criteria Security is mandatory. After that you choose: Availability? Confidentiality? Processing Integrity? Privacy? Your scope is: “SOC 2 Type II for Security and Availability.”

Advantage: you only pay for what is relevant. Disadvantage: if a client says “we also want to see Confidentiality” and you only have Security, you have to be audited again.

ISO 27001: fixed scope with exclusions You must implement all 10 chapters. From Annex A (93 controls) you may exclude what is not relevant, with justification. For example: you have no physical data centre, so physical security controls are not applicable.

Your scope is: “ISO 27001 for [company name] covering [systems/locations].” All controls are reviewed, some excluded with a reason.

Advantage: comprehensive, clients know what they get. Disadvantage: you pay for the full audit even if 20 controls are not applicable.

4. Costs

SOC 2: €30k-€80k first year (average)

• Type I: €15k-€45k
• Type II: €30k-€80k
• Consultancy: €10k-€30k (optional)
• Tooling: €5k-€20k
• Internal time: €20k-€60k

ISO 27001: €45k-€120k first year (average)

• Certification audit: €25k-€60k (Stage 1 + Stage 2)
• Consultancy: €15k-€40k (often needed the first time)
• Tooling: €5k-€20k (may overlap with SOC 2 tools)
• Internal time: €30k-€80k
• Gap analysis + ISMS build-up: €10k-€30k

Why is ISO 27001 more expensive?

• Auditors must be certified ISO auditors (scarcer, more expensive)
• Building the ISMS is more extensive (risk assessments, Statement of Applicability, full documentation)
• Stage 1 audit (document review) + Stage 2 audit (on-site testing) = two audit rounds
• Certification body fees on top of audit fees

Re-audit costs:

• SOC 2: €25k-€60k/year (50-70% of the first audit)
• ISO 27001: €10k-€25k years 2-3 (surveillance), €20k-€45k year 4 (recertification)

Over 3 years: SOC 2 costs €80k-€200k, ISO 27001 costs €70k-€190k. Comparable.

5. Lead time

SOC 2:

• Type I: 3-6 months
• Type II: 6-15 months (the observation period of 3-12 months cannot be shortened)

ISO 27001:

• With consultancy: 6-12 months (ISMS build-up + gap closure + audit)
• Without consultancy: 9-18 months (if you do it yourself, the ISMS build-up takes longer)
• Observation period: at least 3 months of operation before the Stage 2 audit

In practice: SOC 2 Type II and ISO 27001 are comparable in lead time (10-15 months). SOC 2 Type I is faster (4-6 months).

6. Auditor type

SOC 2: CPA firms Only Certified Public Accountants (CPAs) may carry out SOC 2 audits. In the Netherlands: accountants with NOREA experience who can do the ISAE 3000/SOC 2 combination.

Well-known names: Deloitte, PwC, EY, KPMG (Big Four), but also smaller firms such as A-LIGN, Schellman and Prescient (US-focused).

ISO 27001: certification bodies Only accredited certification bodies may issue ISO 27001 certificates. In the Netherlands: accredited by the Raad voor Accreditatie (RvA, Dutch Accreditation Council).

Well-known names: Kiwa, TÜV, DNV, BSI, DEKRA, Certiked.

You CANNOT choose your own auditor outside these groups. This ensures standardisation but also means less freedom of choice.

The overlap: 80% is the same

Good news: if you have one, the step to the other is much smaller.

Shared controls:

• Access management (MFA, RBAC, least privilege)
• Network security (firewalls, segmentation)
• Encryption (at rest, in transit)
• Logging and monitoring
• Vulnerability and patch management
• Incident response
• Change management
• Vendor risk management
• Employee onboarding/offboarding
• Security awareness training
• Risk assessments
• Business continuity/disaster recovery
• Physical security
• Backup procedures

SOC 2-specific:

• Trust Services Criteria framework (you choose which)
• Type I vs Type II distinction
• Observation period evidence with timestamps

ISO 27001-specific:

• ISMS management framework (PDCA)
• Context analysis (internal/external factors)
• Statement of Applicability (SoA)
• Management review is mandatory
• Internal audit is mandatory (you audit yourself first)
• Interested parties analysis

From SOC 2 to ISO 27001: You already have 70-80% of the operational controls. What you need to add: ISMS framework (policies, risk management, SoA), internal audit process, management review. Estimate: 30-40% of the effort of your first SOC 2.

From ISO 27001 to SOC 2: You have the ISMS and controls. What you need to add: evidence collection in TSC format, observation period evidence (timed and dated), attestation report instead of certificate. Estimate: 30-40% of the effort of your first ISO 27001.

When do you choose what?

Choose SOC 2 if:

✅ You target American enterprise clients ✅ You are a SaaS, cloud provider or tech service business ✅ Clients specifically ask for SOC 2 in RFPs ✅ You want to start quickly (Type I = 4-6 months) ✅ You want flexibility in scope (you choose your criteria) ✅ Budget is lower (€30k-€80k for Type II vs €45k-€120k for ISO)

Choose ISO 27001 if:

✅ You target European or international clients (outside the US) ✅ You bid for tenders and public contracts in the EU ✅ You want a public certificate for marketing ✅ You are not only tech, but also other industries (ISO is broad) ✅ You want 3-year validity instead of annual renewal ✅ Clients in Asia, the Middle East or Latin America (ISO is the norm there)

Choose both if:

✅ You have American and European enterprise clients ✅ You are growing internationally and want to serve both markets ✅ Compliance is a competitive advantage (large companies expect both) ✅ You have a budget of €100k-€200k total compliance investment ✅ You want maximum trust signalling to all stakeholders

Combined approach: how do you do both?

Many companies end up with both. How do you tackle that without duplicate work?

Scenario 1: ISO 27001 first, then SOC 2

Timing: Year 1 ISO 27001, year 2 SOC 2

Process:

1. Build your ISMS according to ISO 27001
2. Implement Annex A controls
3. Obtain the ISO 27001 certificate
4. 6-12 months later: start SOC 2
5. Reuse policies, risk assessments and controls
6. Add SOC 2-specific evidence collection
7. Choose your Trust Services Criteria (usually Security + Availability)
8. Audit and report

Saving: 30-40% on SOC 2 costs and time.

Advantage: You have a public certificate (ISO) for marketing while you work on SOC 2.

Scenario 2: SOC 2 first, then ISO 27001

Timing: Year 1 SOC 2, year 2 ISO 27001

Process:

1. Start with SOC 2 (faster, cheaper)
2. Implement controls according to the Trust Services Criteria
3. Obtain the Type II report
4. 6-12 months later: start ISO 27001
5. Reuse controls, policies and evidence
6. Add the ISMS framework (context analysis, SoA, internal audit, management review)
7. Stage 1 + Stage 2 audit
8. Certificate

Saving: 30-40% on ISO 27001 costs and time.

Advantage: You remove sales blockers faster (SOC 2 Type I = 4-6 months), then build towards ISO 27001.

Scenario 3: in parallel (not recommended for a first time)

You can do both at the same time, but it mostly means:

• Duplicate audit processes at the same time
• Two different auditors, two different frameworks
• The team is split across both projects
• Higher chance of burnout and findings
• No synergy benefit (you do everything twice)

Only do this if: you already have one of the two and want to add the other, or you have a dedicated compliance team of 3+ people.

Practical examples

Example 1: Dutch SaaS start-up (25 people)

Situation: Sells B2B SaaS, mainly to Dutch SMB clients, wants to move to enterprise in the Netherlands and the US.

Advice: Start with ISO 27001

• Dutch enterprises are familiar with ISO 27001
• Government tenders often ask for ISO 27001
• A public certificate helps with marketing in the early days
• Costs: €50k-€80k in the first year

If American clients ask for SOC 2 (happens with 2-3 prospects):

• Add SOC 2 Type II in year 2
• Costs: €35k-€50k (30% saving thanks to the ISO foundation)
• Timing: 6-9 months

Example 2: American start-up with European ambitions (50 people)

Situation: Sells in the US, wants to expand into the EU, a German enterprise client asks for “certification.”

Advice: Keep SOC 2 Type II, add ISO 27001

• SOC 2 Type II already obtained for American clients
• Add ISO 27001 for the EU
• Costs: €40k-€60k for ISO (40% saving thanks to the SOC 2 foundation)
• Timing: 6-10 months

Example 3: Fintech with international ambitions (100+ people)

Situation: Payment platform, US + EU + Asia, regulated industry.

Advice: Both frameworks, plus PCI-DSS

• SOC 2 Type II for American financial institutions
• ISO 27001 for European banks and Asian clients
• PCI-DSS because you process card data
• Phased: SOC 2 → ISO 27001 → PCI-DSS over 2 years
• Total investment: €200k-€350k over 2 years
• Synergy: many controls overlap, saving 40-50%

Total cost picture over 3 years

Conclusion: ISO 27001 is cheaper over 3 years (surveillance vs annual full re-audit). But SOC 2 has lower entry costs. Both together is an investment, but gives maximum market reach.

Frequently asked questions

Can I skip SOC 2 with an ISO 27001 certificate?

It depends on your client. Some American clients accept ISO 27001 as an equivalent. But many American procurement teams have SOC 2 hard-coded in their vendor risk frameworks. You cannot get around it in that case.

Can I skip ISO 27001 with a SOC 2 report?

The same story: European tenders and public contracts often explicitly ask for an ISO 27001 certificate. SOC 2 is unfamiliar to many EU procurement staff.

What is easier?

SOC 2 Type I is the fastest and cheapest to start. ISO 27001 is comprehensive but takes longer. Both are serious projects that take 6-15 months the first time.

Can I do both with the same tooling?

Yes, compliance platforms such as Vanta, Drata and Secureframe support both frameworks. You pay €10k-€25k per year for both together (compared with €8k-€18k for SOC 2 alone).

Do I need different consultants?

Not necessarily. Many consultants do both (ISO 27001 and SOC 2). Check their experience with both frameworks. If they know both, they can create maximum synergy.

Summary: the pragmatic choice

For Dutch/European SaaS: Start with ISO 27001. Add SOC 2 when American clients ask for it.

For American start-ups: Start with SOC 2. Add ISO 27001 when you are growing seriously internationally.

For enterprise, fintech or healthcare with global ambitions: Plan for both from the start, but sequenced (first one, then the other). This maximises synergy and spreads the investment.

For serial entrepreneurs who have already built several companies: You probably already have experience with one of the two. Start with what you know, and add the other when your team is large enough (50+ people) to maintain both.

More information

• SOC 2 main page – Everything about SOC 2
• ISO 27001 main page – Everything about ISO 27001
• SOC 2 costs – Detailed costs
• ISO 27001 costs – Detailed costs
• ISO 27001 vs other standards – Broader comparison