Financial transaction processing system

An automated method of card acceptance for processing of financial transactions originating at a point of sale store site computer system for approval by a remoe computer system, said method comprising:

• reading a primary account number from a financial transaction card presented for transaction payment,
• comparing the primary account number with a database of card bank identification numbers in said store site computer system and determining whether the transaction is (a) known to be capable of being settled using a debit point of sale transaction network, (b) known not to be capable of such settlement and (c) unknown to be either (b) or (c);
• the transaction is known to be capable of being settled as a debit transaction, requesting input of a PIN and upon entry of the PIN, settling the transaction through a debit point of sale transaction network,
• when it is determined that the transaction is known not to be capable of such settlement, settling the transaction through a credit transaction network;
• and
• when it is determined that the transaction is unknown to be either (a) or (b), requesting additional information from the card holder with respect to clarifying whether the transaction is to be settled as a PIN-based debit transaction or non-PIN based transaction and thereafter using the appropriate PIN-based settling through the debit point of sale transaction network or the credit network.