What each vendor actually publishes (and the marketing copy you should ignore)
**OpenAI** maintains four distinct policy surfaces, and the differences between them are load-bearing for procurement. The consumer privacy policy at https://openai.com/policies/ covers ChatGPT Free and Plus and is the only surface where 'we may use your inputs to improve our models' is the default state. Users can turn this off in Data Controls, but it remains the only OpenAI product where opting out is required rather than automatic. The enterprise privacy commitments at https://openai.com/enterprise-privacy/ govern ChatGPT Team, Enterprise, and the API by default — and explicitly state that customer business data is not used to train models. Reading only the consumer policy and assuming it applies to your API usage is the single most common mistake security teams make.
The API-specific data-usage page at https://platform.openai.com/docs/models/how-we-use-your-data is the authoritative reference for what happens to a single API call: inputs and outputs are retained for up to 30 days for abuse monitoring, then deleted. Fine-tuning data is kept inside your organization and not used for base-model training. The trust portal at https://trust.openai.com/ then provides the live evidence — SOC 2 Type II reports under NDA, the current sub-processor list, GDPR posture, and the transparency report on government data requests. Treat these four pages as one document, not four.
**Anthropic** publishes a parallel set with slightly different structure. The privacy policy at https://www.anthropic.com/legal/privacy covers both Claude.ai and the API at a high level. The commercial terms at https://www.anthropic.com/legal/commercial-terms are the contract-grade document that governs API and Enterprise customers — Section 5 is the section your legal team will read first, covering data ownership, training carveouts, retention, and indemnification. The trust center at https://trust.anthropic.com/ mirrors OpenAI's: SOC 2 reports under NDA, sub-processors, and security documentation. The acceptable use policy at https://www.anthropic.com/legal/aup is enforced uniformly across Claude.ai and API.
The structural difference worth flagging: OpenAI separates 'consumer privacy policy' from 'enterprise privacy commitments' as two distinct documents. Anthropic keeps a single privacy policy and lets the commercial terms carry the enterprise carveouts. Operationally this means an OpenAI procurement review needs to pull two URLs; an Anthropic review needs to pull the privacy policy plus the commercial terms. Neither approach is better — but if your DPO is used to OpenAI's structure and pulls only the Anthropic privacy policy, they will miss the training-opt-out language that actually lives in commercial terms.
Marketing copy to discount on both sides: 'we don't train on your data' is true with caveats. The caveat is abuse monitoring — a small percentage of inputs flagged by automated safety classifiers are reviewed by humans, retained longer than 30 days, and can be used to improve safety classifiers (not the base model). Both vendors disclose this. Neither markets it. If your compliance use case requires zero human review of any input under any circumstances, you need ZDR — and even ZDR has limits we cover in the deep-dive below.
The other marketing claim to verify: 'enterprise-grade security.' Both vendors hold SOC 2 Type II — OpenAI publishes the audit firm and the date range under NDA at https://trust.openai.com/, and Anthropic does the same at https://trust.anthropic.com/. Both hold ISO 27001. The difference is in the sub-processor stack and the optional certifications (HIPAA BAA, ISO 27018, ISO 27701). Get the current attestation letter before signing; do not rely on the marketing badge.