A method for verifying permission to use a payment system such as an electronic credit card, using a hand held communication device such as a smart phone, where the customer presents the communication device to a merchant who extracts account information from the hand held device, and the hand held device generates a transaction code that is shared with the merchant and sent by both to a financial institution. The financial institution sends a new random code to the user and the merchant, which can be compared to verify the user's account and the financial institution's approval of the transaction.