When we register a domain for our customers we always list our customer as the "Registrant". Their information is also listed as the administrative contact and as the billing contact. We list our information as the technical contact.

Domain name registration is not the same as ownership. Its more appropriate to consider a domain name leased. You can register a domain name year after year or for as many years as you wish and not loose it but ultimately if you decide not to continue paying for the domain it will be returned to the public domain and can be registered by somebody else.