Method for self-checkout with a mobile device

A method for purchasing an item using a mobile device comprises executing a first application on a server and receiving at the server from a mobile device identification information for each item to be purchased. A second application is executed in response to receiving the identification information. The server creates an order associated with the session including item information based upon the received information and dynamically generates a unique identifier representing the order. The unique ID is stored in a state container for later retrieval. Item information is transmitted to the mobile device including a virtual shopping cart that is representative of the stored order, accessible on the mobile device, and associated with an optical machine readable representation dynamically generated by the mobile device to include the unique ID. A terminal scans the machine readable representation and extracts the unique ID which it uses to retrieve the order information from the server for completion at the terminal.