registrant
Also known as: registrant contact, domain owner
The legal entity named on the domain lease, the person or company that actually owns the domain. Distinct from the registrar (the company selling the lease) and the technical / billing contacts.
The registrant is the customer named on a domain’s lease record. They are the legal owner. The registrar holds the lease on the registrant’s behalf and runs the customer-facing portal, but the registrant’s name in WHOIS / RDAP is the source of truth about who controls the domain.
Why this matters for an MSP: when onboarding a new customer, run a WHOIS lookup before doing any work. If the registrant still shows the previous IT provider or a long-departed employee, the customer does not actually control the domain yet. Update the registrant first; everything else (transfers, DNS changes, renewals) depends on it.
Most TLDs also distinguish administrative, technical, and billing contacts. The registrant is the only one who legally owns the domain.