Abstract: An integrated shopping and mobile payment system and method makes in-store checkout flow at a retail store smooth, efficient and intuitive to the customer to thereby improve the customer's experience as well as reducing an amount of time spent at the checkout by both the customer and retail store sales associate. The system and method can reduce long checkout lines during peak period and allow retail store sales associates to spend more time on the sales floor helping customers and increasing sales. A mobile wallet associated with each customer can be used as the mechanism to compute an order, determine and apply offers and loyalty rewards, and give the customer a single click checkout experience at a point-of-sale device in the retail store.