An Interchange Party Computer System (“IPCS”) comprising : a plurality of units of allocated resources, configured for a lender party, broker party, transaction party and/or investor party, each unit of allocated resources including one or more administrator user interfaces that allow a participating party to manage its allocated resources and define which of its users and which other participating parties may access its allocated resources and use elements thereof, wherein at least one of the allocated resources include database allocated resources that are managed by the participating party assigned the resources, the allocated resources for the database being accessible and usable by a participating party on terms defined by the participating party responsible for managing the database allocated resources wherein at least one of the allocated resources include at one or more modules selected from the group of : a Rate and Loan Program Module that includes means to define loan programs or search defined loan programs in a database, an Automated Underwriting Module, a Mortgage Pools Module; a File Status and Transaction Party Module, which includes means to do two or more of : assign tasks, present task status, control viewing of task status, assign viewing privileges, monitor satisfaction of lender conditions, and upload loan documentation that are managed by the participating party assigned the resources; the allocated resources for the selected modules being accessible and usable by a participating party on terms defined by the participating party responsible for managing the selected modules allocated resources.