I am in the same boat and have turned a blind eye to it for the past seven years but no more I am making a list of all the ones in my area to report there are a lot of them and it has affected my work I recently gave 11 estimates and didn’t get the work but they got someone I know to do it on the black and that was the last straw for me. I to would like help on what information I need to supply to the authorities. please help....