Domain locking is a free security enhancement offered by Yahoo! to prevent unauthorized transfers of your domain to another registrar or web host by "locking" your domain name servers. When your domain is locked, you'll be substantially protected from unauthorized third parties who might try to misdirect your name servers or transfer your domain without your permission. You will also be unable to inadvertently make changes to your name servers that could prevent Yahoo! from hosting your domain services properly. Learn more about changing name servers.
To make changes to your domain name servers, you will need to sign in to the Domain Control Panel and turn off domain locking. (We recommend turning locking off only in the event that you need to make such changes.) Learn more.
Please note that domain locking is available only for domains registered through Yahoo! after January 22, 2001 (or, for Merchant Solutions customers, after March 23, 2001). If you'd like to activate locking for a domain you have purchased elsewhere and redelegated for use with your Yahoo! plan, please contact your domain registrar and ask about the availability of this feature.