How to find a TLD WHOIS server

A TLD WHOIS server lookup identifies the registry host that can answer for names under a top-level domain before a second-level domain query moves to registration details. Starting from IANA prevents a copied server list or default client from sending evidence to a stale or unrelated registry.

IANA's WHOIS service accepts top-level domain labels on port 43 and returns the root-zone delegation record. A non-empty whois: field is the legacy registry WHOIS server; the nserver: lines describe TLD delegation and do not prove the authoritative DNS for a domain under that TLD.

Some TLDs do not publish a legacy WHOIS endpoint. A blank whois: field or a missing TLD record means the evidence should name that absence and move to the registry web or RDAP path instead of guessing a server.

1. Query IANA for the top-level domain label.

   $ whois -h whois.iana.org -p 43 com
   % IANA WHOIS server
   % This query returned 1 object
   
   domain:       COM
   
   organisation: VeriSign Global Registry Services
   ##### snipped #####
   whois:        whois.verisign-grs.com
   
   status:       ACTIVE
   source:       IANA

   Use the TLD label without the leading dot. The -p 43 option keeps the WHOIS port explicit for clients that do not map the default service name.

2. Confirm that the IANA record matches the TLD being checked.

   domain:       COM
   source:       IANA

   A TLD record identifies the registry layer for names under that top-level domain. It is not the registration record for example.com or any other second-level domain.

3. Copy the non-empty whois: field as the TLD registry WHOIS server.

   whois:        whois.verisign-grs.com

   Related: How to select a whois server

4. Treat a blank whois: field as no published legacy WHOIS server.

   $ whois -h whois.iana.org -p 43 mil
   % IANA WHOIS server
   % This query returned 1 object
   
   domain:       MIL
   ##### snipped #####
   whois:
   
   status:       ACTIVE
   source:       IANA

   Do not invent likely hostnames such as whois.<tld> when IANA does not publish a server. Use the registry information, RDAP, or the page's required evidence path instead.

   Related: How to query RDAP for a domain

5. Query the selected TLD server for a domain in that zone when domain-level evidence is needed.

   $ whois -h whois.verisign-grs.com example.com
      Domain Name: EXAMPLE.COM
      Registry Domain ID: 2336799_DOMAIN_COM-VRSN
      Registrar WHOIS Server: whois.iana.org
      Updated Date: 2026-01-16T18:26:50Z
      Creation Date: 1995-08-14T04:00:00Z
      Registry Expiry Date: 2026-08-13T04:00:00Z
   ##### snipped #####

   Related: How to query a domain with whois
   Related: How to follow a WHOIS referral server

6. Save the IANA record when server choice must be attached to a ticket or handoff.

   $ whois -h whois.iana.org -p 43 com > com.iana.whois

   Related: How to save raw whois output

7. Record the server and selection source with the saved evidence.

   TLD: com
   Selection source: IANA WHOIS record
   TLD WHOIS server: whois.verisign-grs.com
   Evidence file: com.iana.whois

   The check is complete when the saved IANA record names a non-empty TLD WHOIS server that answers for an in-zone domain, or when the saved record proves that IANA does not publish a legacy WHOIS server for that TLD.