Buyer, vendor and third party computer systems are disclosed together with a related method for enabling a prospective Buyer to browse a Vendor's website to purchase goods or services. According to one aspect of the present invention, the Buyer's computer system automatically extracts purchase information from the Vendor's website from which the Vendor can identify the Buyer's purchase. According to a further aspect of the present invention, the Buyer's computer system transmits, under control of the Buyer, confirmation to the Vendor that a third party has been instructed to pay the Vendor for the Buyer's purchase. In a yet further aspect of the present invention, a third party's computer system transmits to the Vendor confirmation of receipt of an instruction from a Buyer to pay a Vendor for goods or services.