Thick vs Thin WHOIS

Thick and thin WHOIS describe two models for storing [[registrant]] contact data in a TLD's [[whois|WHOIS]] system. In the thin model, the [[registry-operator|registry]] stores only technical data (nameservers and [[registrar]] of record), while full contact details are held by the individual [[registrar]]; queries must be forwarded to the registrar's own WHOIS server for complete records. In the thick model, the registry centralizes all contact data — registrant, administrative, and technical contacts — in a single authoritative database. ICANN mandated that .com and .net migrate from thin to thick WHOIS in 2013, improving data consistency. All new [[gtld|gTLDs]] operate thick WHOIS under the 2012 [[raa|RAA]].