A mortgage information exchange platform implemented in software executable on a web server facilitates information exchange between online brokers and mortgage lenders. Using a web browser, brokers can search their lenders' products and pricing online to find the best loan options for customers. Initially, a rating engine in the platform exposes to the broker a set of one or more generic mortgage lender profiles. In response to entry by the broker of given data from a prospective customer, a given generic mortgage lender profile is applied to the data to identify a set of one or more specific wholesale lenders who meet criteria specified in the given data. The broker then makes a selection of one of the candidate wholesale lenders listed. In response, the rating engine is instantiated with a set of unique lender characteristics for use by the broker in completing an online mortgage transaction.