A mobile checkout system and method for completing a purchase transaction to purchase items from an internet merchant. A user browses and selects items for purchase from the merchant through a shopping application or browser. During the processing of the transaction, a checkout application installed on a mobile communication device is launched. The checkout application receives a checkout token created by a checkout server that identifies the purchase transaction. The checkout application uses this token and communicates with the checkout server to cause the checkout server to complete the purchase transaction. When the transaction is complete, the shopping application or browser is relaunched and a results page is displayed.