Excellent advice from previous post. Id just like to add that in my state a expressed mechanics lien is applied when work is done. Their vehicle is the collateral. I have it clearly posted in the office that payment is due immediately upon completion. Also if they leave it past the payment grace period there is a $20 per day storage fee. I also have a clear it don't budge until its paid in full policy, no exceptions. I do not accept checks, just cash or card. I've strictly followed these policies for the past 8 years and have had no issues getting paid. Remember its all clearly posted so they know when they step in the door. . . Hope this helps