I think the bank's name listed on here itself could cause something in motion for payment to CMS.  Assigning rights over is done more than people think - in fact there are services that will buy your account receivables, which is something I would do before I ever wrote anything off.  I have never written anything off.  One abstracting firm here in Texas that I know of actually takes a credit card number and preauthorization when signing a company up.  It is never used unless the invoices become delinquent over set period.  This is one of the bigger abstracting firms and the other bigger abstracting firm I know of does charge a 5% late fee on all invoices over 30 days.  I don't see why any smaller abstracting businesses should expect anything less.