We don't currently have a mechanism to record the first date that we supply materials or labor to a site when we are a subcontractor. However we usually require a down payment upon placement of an order, or when we don't we would be invoicing within a couple weeks of first supplying materials or labor. Could we use the first invoice date as a trigger for sending the statutory notice to the property owner? Does the statutory notice have to list the date of first supply? (This is for any state that requires statutory notice - not GA as it made me pick a state below.)