net 30 terms, invoice exactly on time NEVER late, “please find attached invoice N, also kindly following up on invoice N-1 which is now past due”, each invoice lists invoice history and payment status (red if overdue), solvent companies will respond, insolvent companies will ignore, send a polite second reminder at 1 week, all solvent companies will respond and remedy here, if no reply send notice of breach at 2 weeks, even insolvent companies will reply to this, they will lie and tell you payment is en route but it will get stuck over some technicality, follow breach process exactly, disengage services after cure period expires and hand it to collections. If your customer is not communicating with you about invoices THEY ARE NOT SOLVENT. If payments are slowing down and tardiness is increasing, they are not being forgetful, THEY ARE RUNNING OUT OF MONEY. They are fundraising behind the scenes and they are hoping for the best while transferring risk to you, or their customer is delinquent and they are aligning payments to transfer that risk to you. Most customers see themselves as good and honest, they are mostly not supervillains trying to screw their counterparties at every opportunity, but they are also taking on hidden business risks and they are underwriting that risk with assumptions like “this payment aligns with this source of cash and everything is balanced and proper”. The moment their assumptions are violated, the moment a risk appears that they don’t consider part of their risk model, or a hope/expectation did not pan out, they will experience anxiety and fear, they will tighten their control over their cashflow to try to establish agency and fortify themselves against the threat.

The relationship is NOT more important because THEY ARE NOT SOLVENT. Do not allow subcontractors to send their own invoices, you must do this yourself to ensure that all communication is exactly on time and never late. Lateness and inconsistency on your side erodes your ability to run a tight collections process, because if you are lackadaisical about payments then they can be too. When you lose control of collections it is not because of text vs email or language, it is because you don’t respect your own process and therefore they don’t respect it either. And when the water gets choppy, they will not think twice (they will not even think at all) about pushing on boundaries because you did not clearly establish them. They are facing a threat, their amygdala is in control, they may not even consciously realize they are doing it. But your process will make that boundary a bright red line, it will force them to make screwing you a conscious decision. And you will know exactly where you stand at all times.