We are an electrical contractor working with a particular builder on a few houses. Up to this point they have not required us to sign lien waivers upon receiving payments on the projects, but we currently have some past due invoices with them and they are refusing to pay until we have turned in signed lien waivers for the most recent payments. The issue I'm having is that these are open projects, with balances left on the contracts. The waivers they've provided do not make it clear that there is still any balance left on the project and states that all bills have been paid on the project and there are no outstanding bills. The only amount specified on the waiver is the payment made at the time it was issued. If we sign this, doesn't that set us up to forgo our rights of lien if they don't make their future payments? They never sent a contract for the projects so our only 'contract' is our proposal for the job that they signed, which lists our billing terms. This is a customer we've been having issues with recently and they have been consistently paying late. After our current projects are finished, our relationship with this builder is ending and both parties know it, so I don't want to set us up for signing away what little leverage we have since they have nothing to lose by not paying us now. I want to ensure that I do not set us up to be unpaid for our work, without legal recourse. They have shown very shady business practices and seem to be up to something with their other subcontractors as well. We have been diligent in getting change orders approved in writing and have emails with them acknowledging to an extent that they owe us payment for the open invoices, but won't pay until their waivers are signed. Is this enough or would it all go out the window if we were to negligently sign a waiver saying there is no open billing left on the project? Thank you so much in advance for your help. We are a small company and this customer owes us tens of thousands of dollars in total, so a misstep could greatly hurt us.