Abstract: A secure payment method and system for payment for a product in electronic form comprises a customer's terminal and a merchant's terminal connected by a communications network. A customer uses a customer's terminal to request a product and at the customer's terminal, it is determined whether the product has previously been paid for by identifying if there is a corresponding transaction receipt stored at the customer's terminal. If there is a corresponding receipt this is transmitted with the request to the merchant's terminal. At the merchant's terminal, when the request is received, if there is an accompanying transaction receipt, the product is transmitted to the customer's terminal. If there is no accompanying transaction receipt, the transaction is recorded and a transaction receipt is generated and transmitted to the customer's terminal.