When a buyer's debt to a seller cannot be paid using an account issued to the buyer by an issuer within a payment processing system, then either or both the seller and the buyer are solicited to conduct future transactions payable on the account. If the debt can be paid using the account, then a sub-account...http://www.google.com/patents/US20080133409?utm_source=gb-gplus-sharePatent US20080133409 - PAYMENT PROCESSING SYSTEM DEBT CONVERSION NOTIFICATION
