An in-store mobile payment system and method can facilitate the use of a user's mobile device to facilitate payment for products purchased at a store. The user can take a picture of a product being purchased or can take a picture of a bar code for the product. The picture can be taken with the user's mobile device and can be used to identify the product. A payment provider can provide a unique PIN code for the transaction. The user can enter the PIN code into a keypad of the merchant and/or can swipe a card with a card reader of the merchant to complete the transaction. Thus, the user can avoid the inconvenience of waiting in line at a checkout counter and the merchant can reduce the store's overhead by eliminating at least some checkout counters and checkout clerks.