1. A method for providing procurement services to a plurality of customer companies, comprising the steps of: establishing a user profile for each person authorized by a customer company to access said procurement services; associating each said company with a company group of related companies; said user profile specifying for each said user a user company and company group; providing for each procurement resource to be shared among said users a resource profile specifying for each resource those said companies to have access to said procurement resource; and responsive to said user profile and said resource profiles, controlling user access to said procurement resources.