UNITED KINGDOM – After more than a year of testing, Shell U.K. and PayPal have launched the Fill Up & Go smartphone app to customers across the United Kingdom, reports The Telegraph.

Fill up & Go is available through the Shell Motorist app, which requires users to link the payment feature to their PayPal account and create a five-digit PIN that’s required for logging into the app. To pay for fuel through the app, users scan the QR code on the pump using the app, and then choose the maximum amount to pre-authorize (starting at £5), according to the news source. When the “start refueling" message  appears on their smartphone screen, users can begin filling up; the app activates the pump and stops dispensing before reaching the maximum spend limit. Customers are only charged for the amount of fuel dispensed.

Shell customers can check which stations throughout the U.K. offer the service by using the app or the Shell website. In the U.K., PayPal has about 19 million active customer accounts, writes the Telegraph.