Operational guidance, not legal advice. This page distills named public sources (regulator guidance and industry practice). It is not a legal determination, not a notification decision, and not a substitute for your counsel, insurer, or a retained DFIR firm. Verify applicability and current deadlines for your facts and jurisdiction.
What are security audit independence requirements?
Last verifiedWhat are security audit independence requirements? Threats include self-review and familiarity; safeguards vary by scheme. Not legal advice. Does not determine YOUR engagement structure.
Security assurance guidance, last verified 10 September 2026 against AICPA Code ET §1.200 and ISO/IEC 17021-1:2015 §5. Binding force varies — AICPA rules bind AICPA members; ISO/IEC 17021-1 binds accredited CBs. Customer contracts may add requirements. Not legal advice.
Threats and safeguards
| Threat | Example | SOC 2 (AICPA) | ISO CB (17021-1) | Kind of text |
|---|---|---|---|---|
| Self-review | Auditor certifies their own readiness work | ET §1.200 — prohibited without safeguards | §5 consultancy limits | Professional standard |
| Self-interest | Audit fee tied to selling remediation | Fee dependence threats | Commercial pressure on CB | Professional standard |
| Familiarity | Long-standing advisor becomes auditor | Partner rotation; cooling-off | Auditor rotation rules in scheme | Professional standard / best practice |
| Advocacy | Auditor lobbies customers on YOUR behalf | Advocacy threats under ET | Marketing certificate as product | Professional standard |
Legal vs professional-standard vs best-practice
- Legal requirement: rare direct statute on auditor independence for private SOC 2 — but public-company rules exist elsewhere; counsel applies to YOU.
- Professional standard: AICPA Code for CPA firms; ISO/IEC 17021-1 for accredited CBs — binding on those providers.
- Best practice: separate prep and audit; document threats in engagement file — ShipReadyMetrics recommendation.
- Customer contract: may require specific independence language — not universal law.
Engagement independence checklist
- Independence questionnaire completed and retained?
- Prior services by auditor/CB disclosed?
- Fees not contingent on unqualified opinion / certificate?
- Subcontractors bound by same independence rules?
- Management representation addresses relationships?
- Customer notified if threat identified mid-engagement?
What to do now
- Complete the engagement independence checklist before signing.
- If any threat row applies, get written safeguard analysis from the CPA/CB.
- Read same-firm-prepare-and-audit guide if one vendor sold prep and audit.
- Use evidence-review trail in ShipReadyMetrics as YOUR auditable prep record — not a substitute for auditor independence.
Checklist
- Threat assessment documented?
- Safeguards accepted by auditor/CB in writing?
- No advocacy or remediation sold by audit partner?
- Rotation plan if familiarity threat exists?
Where this shows up in ShipReady Metrics
Evidence review with met-verdict overlay gives an auditable prep trail independent of the CPA/CB. ShipReadyMetrics does not perform attestation and does not resolve independence — the signing auditor does.