Why isn't my whois result the same from one whois search engine to another?

Question

I'm trying to register for an EV SSL certificate, but the company requires that the registrant match the company submitting. They've been unable to do this because they are getting a whois result that doesn't match the whois result that I'm getting through another site. Why does the whois result differ between sites?

Answer 1

That depends on what is different between them. If you read the RFC for WHOIS, you will find that the protocol consists of two pieces: the client sends a CRLF terminated string to the server and the server responds with a bunch of CRLF lines and closes the socket.

from the RFC:

client                           server at whois.nic.mil

open TCP   ---- (SYN) ------------------------------>
           <---- (SYN+ACK) -------------------------
send query ---- "Smith<CR><LF>" -------------------->
get answer <---- "Info about Smith<CR><LF>" ---------
           <---- "More info about Smith<CR><LF>" ----
close      <---- (FIN) ------------------------------
           ----- (FIN) ----------------------------->

No part of the protocol covers what that block of text should contain. This means that the format of the information can vary wildly between WHOIS servers.

If it isn't just the format that is varying, but the data itself, well, without knowing what is different and which hosts you are querying, I don't have enough information to guess what might be wrong.