Service Provider

A service provider (SP) is the application or service a user wants to access through single sign-on (SSO). It relies on an identity provider (IdP) to authenticate the user instead of collecting the user's credentials itself.

How a service provider works

In a SAML sign-in flow, the SP can send the user to the IdP for authentication. After the user signs in, the IdP sends a SAML response to the SP's Assertion Consumer Service (ACS) endpoint. The SP validates the response before creating a session for the user. The flow can also begin at the IdP.

For example, an employee might open a work application and be redirected to their organization's IdP. After authentication, the employee returns to the application. In this flow, the work application is the SP and the organization's sign-in service is the IdP.

Service provider is the term used for this role in SAML. In OpenID Connect (OIDC), the application that relies on authentication from an OpenID Provider is called a relying party.