Fitbit has launched its payments processing app in the U.K.

Fitbit Pay, the wearable tech firm’s answer to competitor giants like Apple Pay and Android Pay, will be available initially with one bank in Britain — fintech start-up Starling.

Starling customers in the U.K. can now use Fitbit’s Ionic smartwatch to make contactless payments in stores.

“Starling Bank was founded to empower consumers to take control of their money and better manage it on the move, so Fitbit Pay is a perfect partner for us,” Starling CEO Anne Boden said in an announcement Tuesday.

Starling is a challenger bank — one of many small retail lenders set up with the intention of eating away at the consumer base of larger banks.

It is also the first British bank to offer Apple Pay, Android Pay and Fitbit Pay on its app; it introduced the former two features last month.

Both Apple and Android’s payments apps have made significant partnerships with Europe’s big banks.

Apple Pay is currently available with a number of lenders, including Italy’s UniCredit, Russia’s VTB Bank and Britain’s Barclays.

Banks that support Android Pay, meanwhile, include Spain’s Santander, Britain’s Royal Bank of Scotland and Ireland’s Ulster Bank.

San Francisco, California-based Fitbit’s payment processor is currently offered mainly by U.S. banks. The only European lender other than Starling to offer payment via Fitbit is Swiss bank Cornèrcard, according to the tech company’s website.

Fitbit said its partnership with Starling represented an opportunity for international expansion.

“By working with banking institutions globally, we have the opportunity to expand our reach around the world to drive engagement with existing customers and attract new ones,” Des Power, senior vice president and managing director at Fitbit International, said in a statement Tuesday.