Do I have to send a Pre-lien Notice Letter for every month I perform work on a project?

It is recommended to send notice for every month you perform work in the event of non-payment. Since the deadlines in Texas laws are strict and relatively narrow. It is very important for Subcontractors and Sub-subcontractors (1st and 2nd Tier contractors) to send notice of outstanding invoices for each month as soon as possible to protect their right to file a lien claim.
It is a low cost letter that could prevent expensive litigation costs in the future.