OpenTable, the world’s largest online restaurant reservation service, is testing a new payment process to allow customers to pay using mobile devices.

In June, OpenTable paid US$11m in stock to acquire JustChalo, a mobile technology company that's been working on a payment app. The system is now being tested in 20 restaurants and OpenTable is planning on having it ready to deploy in San Francisco by the end of the year. Users will be able to review their bill, add a tip and complete the payment using the new app on their mobile device.

Restaurants using the service will only pay the regular credit card transaction fee.

The aim is to attract more people to use OpenTable, which charges restaurants for reservations made through its service while also making a service charge for the use of its equipment.

The company, which works with 28,000 restaurants worldwide, says it's being cautious with its planned release of the system because of the potential implications caused by mobile payment.

Paying via an app would reduce the amount of time customers have to wait to pay their bill, but waiters could also mistakenly think they're leaving without paying. A potential solution would involve restaurant employees being sent a notification when a customer has paid via a mobile device.

View OpenTable’s website here.