Went out on Saturday to stop leaking toilet on floor. Found three toilets in reconditioning need. Found too much water pressure in house. Temporary fixed the leaks (3 leaks) and told customer the needed repairs - toilets reconditioning and valve on main line to reduce pressure. Went home/office and email the invoice ($215.00) and put in writing the work needed and the consequences for no fixing the problems ASAP. Customer didn't pay and didn't put attention to the warnings. After the 4th e-mail I notified the owner that I was filing a preliminary notice (lien) .. not answer. I filed for $363.50 and bingo! the customer suddenly appear and he had to pay the entire $363.50 or a final lien was ready to file.
If a customer, without a reasonable excuse doesn't pay after the 18th day of the invoice I immediately file the preliminary. Surprisingly I never lose and invoice. Now this is Arizona where you have up to 20 days from the moment you start the work to file, but I am sure similar laws are in all the states. File them!!!