Retention limit + log purge on AI vendor side
Demonstrate that the organization has contractually mandated and verified that AI vendors enforce automated data retention limits and purge customer interaction logs within defined timeframes.
Description
What this control does
This control ensures that AI service providers automatically delete or anonymize logs, prompts, model inputs, outputs, and telemetry data according to contractually defined retention periods. It requires vendors to implement automated purge mechanisms that remove customer data from production systems, backups, and training pipelines after the agreed timeframe (e.g., 30, 90, or 180 days). This prevents indefinite retention of potentially sensitive or proprietary information submitted to third-party AI platforms and limits exposure from vendor-side breaches or unauthorized access.
Control objective
What auditing this proves
Demonstrate that the organization has contractually mandated and verified that AI vendors enforce automated data retention limits and purge customer interaction logs within defined timeframes.
Associated risks
Risks this control addresses
- Indefinite retention of proprietary business data, trade secrets, or intellectual property submitted to AI models
- Unauthorized training or fine-tuning of vendor models using customer prompts and data beyond agreed retention periods
- Extended window of exposure if vendor infrastructure is compromised, allowing attackers to harvest months or years of customer queries
- Regulatory non-compliance due to retention of personal data beyond permissible periods under GDPR, CCPA, or sector-specific laws
- Data remanence in vendor backup systems or disaster recovery archives that persist beyond stated retention policies
- Forensic reconstruction of sensitive queries or outputs from long-term vendor logs during litigation or regulatory investigations
- Insider threat at vendor organization accessing historical customer interaction data for competitive intelligence or malicious purposes
Testing procedure
How an auditor verifies this control
- Inventory all third-party AI vendors and services currently in use, including API-based models, hosted platforms, and embedded AI tools.
- Review executed contracts, data processing agreements, and service level agreements to identify documented retention periods and purge commitments for each vendor.
- Request and examine vendor-provided data retention policies, data lifecycle documentation, and technical specifications describing automated purge mechanisms.
- For a sample of AI vendors, submit a formal data subject access request or vendor audit request to confirm what data is currently retained and verify alignment with contractual limits.
- Review vendor SOC 2 Type II reports, ISO 27001 certificates, or third-party audit attestations specifically covering data retention and deletion controls.
- Test vendor self-service data deletion capabilities (if available) by submitting test queries, waiting for the retention period, and verifying removal through API queries or vendor portal.
- Examine change control records and vendor communication logs to confirm that retention settings have been configured according to contract terms and are monitored for drift.
- Validate that internal procurement and vendor management processes require retention limit clauses in all new AI vendor agreements and track compliance through quarterly vendor risk reviews.
Where this control is tested