A user makes a purchase request through a merchant app on a mobile device, such as by selecting an item for purchase. A mobile SDK of a payment provider is installed in the merchant app. The payment request includes the phone number for the mobile device. The payment provider verifies the phone number of the user and requests approval of the payment from a mobile operator providing wireless communication services on the mobile device. If the request is approved, the payment is charged to the user mobile operator account. The user simply taps a button to select an item to purchase and selects another button to confirm the purchase. Once processing is done, the user is notified on the mobile device of a successful payment.