Plain-English AI definitions for legal professionals. For what bars actually require, see the Legal AI Compliance Register.

Zero data retention (ZDR)

Using AI Last reviewed 2026-06-11

Definition A contractual arrangement in which an AI provider does not store a customer's prompts or outputs after processing the request—data is used to generate the response and then deleted rather than logged.

In more depth

Standard API terms often retain inputs briefly for abuse monitoring; zero-data-retention agreements remove or sharply limit that storage so content exists on the provider's systems only transiently. ZDR reduces exposure if the provider is breached or subpoenaed, and law firms handling privileged material increasingly request it. Verifying what retention actually applies—across the vendor and any subprocessors—is a standard part of AI tool diligence.

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About the editor: MHSB Solutions, Research desk. MHSB Solutions is not a law firm. This glossary is educational information, not legal advice.

Educational information, not legal advice. AI terminology and tools change quickly; definitions reflect usage as of the last-updated date. For what bar associations and courts actually require of lawyers using AI, see legalaicompliance.help and consult a licensed attorney in your jurisdiction.