We are a GC doing a job in Arizona. A cash advance company filed a UCC Lien on one of our subs working on this job. It looks like the cash advance company purchased the accounts receivables of our sub for a certain dollar amount, and the sub is now in default. We received a notice of the UCC Lien in the mail and it asks that we forward all funds owed to our sub to the firm representing this cash advance company instead. The UCC lien states that they are aware we owe the sub money, which we do as it's an ongoing job, but the lien does not mention our project at all. As the GC, we are wary of this and unsure how to proceed. This agreement between our sub and the cash advance company does not include us or our project, and we are not in contract with this 3rd party. We are obligated to pay our sub as we are in contract with them, not this 3rd party. If we don't forward the funds and our sub does not pay the cash advance company, can the cash advance company file a lien on our job? Should we look into issuing joint checks going forward between the sub and cash advance firm? How do we, as the GC, protect ourselves in this situation?