That's odd.... a 3% discount from what fee -- one that you set? or one that they set.  If you set it, markup to include the discount and then give them the discount.  When I took my math course in my paralegal curriculum, retail suppliers usually give a small discount to stores that pay within 30 day periods.  But our business is not in the retail/wholesale arena.  So in our business it sounds like (friendly) hostage or blackmail.  Are you going to do it?  I probably would bill them at the discount depending on the volume they send and the amount of work done on each piece.  Donna