I'm not a contractor nor do I have a license, but I was approached by a woman in January to rig down a truck mounted drilling rig (small scale for geotechnical sampling) mounted on a Ford F550, design, fabricate, and remount the same rig and get it ready for operation. I finished on April 13th, sent an itemized invoice payable on May 9th, a very reasonable amount of $1,050, she paid half the invoice but will not return messages or calls now, even though I have sent a notice of past due. She told me the truck/rig would be put up for sale, point being if she has or does, I won't see another dime. I don't have a contract but I have plenty of proof the work was requested by her, an invoice was requested by her, statements by her that she would pay by the due date, and that the work was completed, tested, and turned over to her. Questions 1. Can I file a mechanics lien? 2. If yes, do I have to give notice before, or after I file the lien? Thanks, Karl