Registry lock
A registry-level lock that requires multi-step out-of-band verification (often a phone call) to unlock. Used on high-value names to prevent registrar-side compromise from triggering a transfer.
When to use
Domains worth $100K+ or critical to a company’s identity (the company’s own brand domain). Most premium registrars charge $40-$100/year for the service.
What it blocks
Not just transfers — DNS changes, nameserver updates, and contact changes all require the manual unlock step.