What is Domain Lock?

Domain Lock, also known as Registrar Lock, is a security status applied by a domain registrar to a domain name. It prevents the domain from being transferred to another registrar, updated (such as changing nameservers or contact details), or deleted without the registrant first unlocking the domain. This lock is enforced by the registry via an Extensible Provisioning Protocol (EPP) status code like "clientTransferProhibited" or "clientUpdateProhibited."

The mechanism works through the interaction between the registrar and the registry. When a registrar sets a lock, it sends an EPP command to the registry to update the domain's status. The registry then returns the domain to any query with the appropriate status codes, rejecting transfer, update, or delete requests until the lock is removed. Domain locks are distinct from registry-level locks (often called Registry Lock), which provide an even higher level of security by requiring manual approval from the registry itself.

In the broader domain management stack, Domain Lock is a standard feature offered by virtually all registrars. It is considered a best practice for any domain owner who does not plan immediate changes. The lock does not affect the domain's normal operation, such as DNS resolution or email delivery. The registrant can remove or reapply the lock at any time through their registrar's control panel, subject to any authentication checks. The absence of a domain lock is a common factor in domain hijacking incidents.