1. A method of providing data of a user stored on a data providing computer system to a data consolidating computer system, the method comprising: receiving from the data consolidating computer system from which an indication was previously received that the user had proved an association with one of a plurality of firms with which data consolidating computer system the user is able to prove an association and on which the user has a first user identifier, at a matching system, a second user identifier that also identifies the user on the data consolidating computer system, and that is different from the first user identifier of the user, and that cannot be used to log the user into the data consolidating computer system, over a first communication facility that is verified by the matching system to be coupled to the data consolidating computer system; checking at the matching system a validity of the user and the firm with which the user had proved the association; and responsive to the checking step: converting by the matching system, the second user identifier into a third user identifier of the user on the data providing computer system that was previously provided by the data providing computer system to the matching system and identifies the user on the data providing computer system and that cannot be used to log the user into the data providing computer system on which the user has a fourth user identifier; and providing the third user identifier by the matching system to the data providing computer system over a second communication facility coupled to the matching system that is verified by the data providing computer system; receiving data of the user from the data providing computer system over the second communication facility responsive to the third user identifier provided; and providing the data of the user received to the data consolidating computer system associated with the second user identifier.