Apparatus and method for purchasing an item via a self-service checkout at a merchant store. The item is associated with a bar code and an anti-theft device. A customer uses their phone to establish communication with the store's transaction host. The phone includes a camera and a programmable memory. The memory includes customer account data. The camera is used to capture and transmit an image of the bar code to the host. The host determines the item's cost from the received bar code image. The customer can wirelessly transmit their account data from the phone to an in-store terminal. The terminal can transmit the account data to the host. The host can accept and use the account data in payment for the item. After customer payment for the item, the host causes the anti-theft device to be neutralized.