When an external user such as a trading partner makes a request into an access point of an application on an application server, that external user can be authenticated as a valid user on the system. The identity of the external user can then be switched to an internal system user identity, such as by pushing new user information on the user stack or by adding internal user context. This internal system user identity allows the user to access resources and applications on the application server that are not available to an external user. The use of this single internal system user identity allows for a single login process that can be used for all resources and applications on the server. The use of an internal user also prevents an external user from accessing those resources unless the user is first authenticated through a proper entry point.