In Florida, I read the private projects are not regulated for retainage practices. As such, we have only been withholding retainage on the actual labor portion. If we buy materials-not thru a sub-contract, we do not hold retainage as this is pass thru cost. Now we have a customer that is fighting us tooth & nail on everything including how retainage should be managed and held. Our contract states- Contractor's application for payment shall show the percentage of satisfactorily completed portions of the work at the end of each 4-week period, less a retainage of 10%. Is there any law or regulation supporting either side of this argument?