The entire domain’s registration information such as address, phone number and mail address are existed in the central databases.
These databases are known as WHOIS databases centre. According to ICANN rules, all of the domain registration centers are required to have correct searching information concerning WHOIS.
It is too important to have accurate information in WHOIS reference, because this information are going to be used in different ways such as domain transfer, awareness of domain expire date, and domain owner contact information.