We have a customer that is requesting an Unconditional waiver on a project. The waiver that they sent over states that it is valid "Through Date: 7/20/2018". We have two projects with them, and the earliest start date is 7/26/2018 which we submitted prelims for. I am weary to sign this unconditional because we have not been paid for our open invoices as of today. He claims that the GC is requesting this unconditional waiver for anything prior to 7/20/2018 because the prelim that we submitted is of course valid for anything 20 days or prior to the submitted date. My question is: If I sign this Unconditional Waiver, does it affect the prelim that I submitted for our jobs?