I take the 1040 as a confession/assessment--its an affidavit to be used as evidence in U.S. Tax Court. On the other hand, when the IRS sends a notice of deficiency it is not yet an assessment until there is agreement. The U.S. Treasurer deals with funds committed to public use. Until there is assessment, the U.S. Treasurer has nothing to expect. Where there is a refund due, the U.S. Treasurer would be holding private property not subject to assessment and might like to know what to do with it.