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 is created unique to the seller and buyer. Transactions between the buyer and seller can be processed using the sub-account including the option of aggregating the debts prior to the processing. The credit limit of the sub-account can be set to match the amount of the aggregated debts.