A service system includes a server that provides a service as a cloud service, and a device that receives the service, wherein a terminal device that is operated by a contract administrator sends identification information of the contract administrator and information related to a contract of the service, to the server, and wherein the server includes a user information storage unit that specifies a role associated with the identification information of the contract administrator, a communication unit that receives the identification information of the contract administrator and the information related to the contract, and an information registration unit that registers the identification information of the contract administrator, contract identification information generated based on the contract, and an operation privilege related to the contract based on the role specified in the user information storage unit, in association with each other, in a contract operation privilege information storage.