Control → Evidence → Test → Finding
This is the habit that separates an audit from a policy review: for every control, know what proves it exists, how you'd verify it operates, and what a failure looks like.
Take human oversight. The control is that a defined high-impact workflow — an automated denial, say — requires human review before it's finalized. The evidence is a review log showing reviewer, timestamp, and decision. The test is trying to push a case through the workflow in a way that should trigger review, and seeing whether the system actually enforces it. The finding, if it fails, is that the workflow completed without logging a review event — meaning the control exists on paper but not in the system.
Or take vendor data retention. The control is that your Enterprise AI vendor deletes customer data within a contractually defined window after termination. The evidence is a deletion confirmation or an exercised audit right. The test is requesting that confirmation, or pulling it from a completed offboarding. The finding, if it fails, is that the vendor can't produce deletion evidence, or the contract never specified a timeline to begin with.
Apply that pattern everywhere in this checklist. A checklist that only asks "does a policy exist?" will pass systems that fail in production.
Audit Questions to Ask
Governance: Who owns this system, and who approved it? Who can stop it? What happens when the model or vendor changes? Is there a standing body reviewing new deployments?
Data: What data enters, and from where? What's the legal basis? How long is it retained, and how is it deleted? Is it truly anonymized, or just pseudonymized?
Security: Has prompt injection been tested? How are the APIs authenticated and rate-limited? Can any user reach data or outputs they shouldn't? Has it been red-teamed?
Compliance: Which laws apply to this specific system? Is a DPIA or impact assessment required — and done? What could you show a regulator today, with no preparation time?
Oversight: Is the documentation current? Can a human actually override an automated decision, and has that been tested? What's disclosed to affected people?
Operations: How is drift detected? How are incidents logged and escalated? Can you reconstruct a specific past decision from logs? How are model or prompt changes approved before release?
How to Conduct an AI Audit
A checklist tells you what to check. This is how the audit itself runs, and it's a different thing:
- Define the scope — systems, business units, timeframe.
- Build or refresh the inventory for systems in scope.
- Confirm ownership for each one.
- Classify systems and risks.
- Map data flows and dependencies, including vendors.
- Identify which regulations and standards actually apply.
- Collect evidence against each domain above.
- Test controls — not just documentation.
- Interview stakeholders to fill what documentation alone can't answer.
- Document findings where controls don't hold up under testing.
- Rate severity.
- Assign owners and realistic remediation deadlines.
- Set retest dates.
- Re-test after remediation.
- Write the final report.
- Move into continuous monitoring so the next audit starts from a stronger baseline.
Findings and Risk Rating
Use a consistent scale — critical, high, medium, low, observation — so remediation effort tracks actual risk rather than whoever escalated loudest.
Here's what a real finding looks like: a customer-support AI assistant logs full chat transcripts, including unredacted card numbers, to a third-party analytics vendor with no data processing agreement in place.
Evidence: sample transcripts and a contract review showing no DPA.
Risk: high — unmanaged sensitive-data exposure to an unassessed third party.
Root cause: no data sanitization before the data leaves the workflow.
Recommendation: filter or anonymize before third-party logging, and get a DPA signed.
Owner and deadline: assigned to the DPO, 45 days, retest scheduled.
An audit report itself should cover: an executive summary, scope, applicable frameworks, methodology, findings by domain, risk ratings, referenced evidence, an assessment of control effectiveness, a remediation plan with owners and deadlines, management's response, and a retest date.
ISO/IEC 42001, NIST AI RMF, and EDPB Guidance
ISO/IEC 42001 is the international standard for an AI management system. It's certifiable but not mandatory — organizations usually pursue it for procurement leverage or to formalize governance that already needs structure. Clause 9.2 requires planned internal audits of the management system; Annex A provides AI-specific controls (impact assessment, data governance, third-party relationships) that map closely onto the domains above, with findings feeding into corrective action and management review.
NIST AI RMF organizes risk management into four functions — Govern, Map, Measure, Manage — running continuously rather than as sequential phases. It's voluntary federally, though increasingly referenced in contracts and some state laws.
Loosely: ownership and policy work maps to Govern, inventory and classification to Map, testing to Measure, and incident response and remediation to Manage.
EDPB's AI Auditing project, run through its Support Pool of Experts at the initiative of Spain's data protection authority, produced a downloadable checklist methodology and a proposed "algo-score" framework for assessing GDPR safeguards in AI systems, completed by an external expert in early 2023. It's aimed mainly at helping data protection authorities structure inspections — it isn't a substitute for a full compliance program and doesn't touch the EU AI Act's non-privacy obligations. But as one of the few regulator-produced auditing methodologies publicly available, it's a useful cross-check for the privacy dimension of your own checklist.
EU AI Act and GDPR: What Actually Applies
The EU AI Act's obligations are tiered by risk category and by your role as provider or deployer — there's no single checklist item that applies uniformly. As of this writing: prohibited practices and AI literacy obligations have applied since February 2025, and general-purpose AI model obligations since August 2025. Following the "AI Omnibus" simplification package that took effect in July 2026, most stand-alone high-risk systems under Annex III now face a compliance deadline of December 2, 2027, and high-risk AI embedded in already-regulated products (Annex I) moves to August 2, 2028 — while transparency obligations under Article 50 still apply from August 2, 2026. These dates are politically live and worth verifying against the European Commission's timeline before you rely on them. Where a system is in scope, audit for: documented classification and role, an ongoing risk-management process, data governance on training/validation/test sets, current technical documentation, sufficient logging, human oversight that's actually effective, tested accuracy/robustness/cybersecurity, Article 50 transparency where relevant, and post-market monitoring.
GDPR doesn't create one universal "AI audit" obligation — it requires accountability, and a DPIA where processing is likely high-risk. In practice that still means: a documented lawful basis, minimization applied to prompts and training data, privacy notices that reflect actual AI processing, data subject rights that work technically (including against fine-tuning data), Article 22 safeguards where decisions are solely automated and legally significant, Article 28-compliant processor agreements, valid transfer mechanisms, enforced retention schedules, and the anonymization/pseudonymization distinction applied correctly rather than assumed.
Generative AI, Agents, and Vendors
Generative AI needs its own pass: know your LLM provider's data-retention and training-use policies, inventory RAG data sources and vector database contents, test for prompt injection and data leakage in both directions, evaluate hallucination rates for your specific use case, put output validation or guardrails in front of anything reaching end users, track model version changes with re-testing triggers, and log the interface itself.
AI agents extend the audit past a static model to whatever actions the agent can take — and not every agent needs identical controls, so scope this to what it's actually permitted to do. Check its identity and ownership, its explicit permission boundaries, which tools and APIs it can invoke, what data it can read or write, whether high-impact actions require a human approval gate that's actually enforced, whether its decisions and tool calls are logged in enough detail to reconstruct behavior, how memory is retained and purged across sessions, whether irreversible actions (payments, deletions, external comms) have controls around them, and whether its actions can be rolled back if something goes wrong.
Third-party AI vendors need their own checklist too: data processing and retention terms, whether your data trains their models and under what opt-out, subprocessor disclosure, current security certifications scoped to the AI product specifically, incident notification timelines, audit rights or an equivalent, and a real exit and deletion process at contract end.
Shadow AI
Shadow AI — employees using AI tools outside any governance review — creates a visibility gap: you can't assess or control risk in systems you don't know are running. Detecting it usually takes a combination of network-level monitoring for AI traffic, procurement and expense review, and employee surveys, since no single method catches everything on its own. Governing it means clear acceptable-use policy paired with sanctioned tools good enough that people don't feel they need alternatives, plus a technical backstop — privacy-first anonymization that sanitizes sensitive data before it reaches any external AI system, regardless of which tool someone reaches for. Policy alone, with no technical enforcement, is asking for voluntary compliance and calling it a control.
Continuous Assurance
A checklist run once a year can't keep up with systems that change weekly. It helps to separate four distinct activities: continuous monitoring (automated, near-real-time tracking of drift and control status), periodic internal audit (a scheduled deeper review), event-triggered review (triggered by a model change, new vendor, incident, or regulatory shift), and formal external audit (independent, sometimes required for certification). What should be watched continuously: model and data changes, vendor changes, regulatory developments, drift, new vulnerabilities, incidents, control effectiveness, new systems entering the inventory, and Shadow AI signals. Done well, a formal audit just confirms what continuous monitoring already showed.
Documentation vs. Actual Control
The most important discipline here is refusing to stop at "do you have a policy?" Every mature audit asks a second question: can you demonstrate the policy is implemented and operating? A human-oversight policy a workflow can technically skip isn't a control. A retention policy nothing automatically enforces isn't a control. A vendor clause promising deletion, never once verified, isn't a control. Test both questions for every item in this checklist — regulators, customers, and internal risk committees increasingly ask the second one first.