A system and a method for a transaction based on a license plate number. A method of providing data for paying for an item, performed by a mobile device, includes receiving a license plate number from a vehicle terminal through short-range wireless communication, selecting a credit card to be used to pay for an item provided in an offline store, and transmitting the received license plate number and information regarding the selected credit card to a payment server. The license plate number and the information regarding the selected credit card transmitted to the payment server are used for the payment server to authenticate the payment of the item, together with information regarding a license plate number provided from a store terminal of the offline store to the payment server.