I have a multiple invoices in Texas that have gone unpaid. What do I need to do to get liens filed? I am currently sending monthly notices but would like to know when I can start filing liens on those invoices
You really should retain a construction attorney to review and evaluate your legal position based on the contract and pertinent documents. The right to be entitled to file a mechanic's lien is set out in Texas Property Code Chapter 53, and you really need to make sure that if you file a lien, you have properly and appropriately done so.
Filing an invalid lien could subject you to liability under the Texas Fraudulent Lien Act, and you could be liable for statutory damages of $10,000, or actual damages, whichever is greater, plus attorney's fees. Facing such a claim would add insult to injury.
The legal analysis would start with a review of your contract(s), and then extend to any communications which have occurred, and to the nature of the project (commercial or residential or homestead),, and your position within the contracting hierarchy on the project.
Good luck.