Spanish banking giant Banco Santander— the world's 19th largest bank in 2017 – recently launched “Santander One Pay FX”, a blockchain-based international payment service that uses Ripple’s xCurrent technology to allow retail customers to make same-day cross-border payments.

Currently, this new service is only available to retail customers in the UK, Spain, Poland, and Brazil, but it will become available in other countries — most likely, the United States and the other Euro-zone countries — in the coming months.

“Santander One Pay FX” allows customers to specify the exact amount the beneficiary will receive in the destination currency. For now, international payments are only guaranteed to be delivered the same day or at worst the next one, but this summer instant transfers will become possible.

In Santander’s press release, Ana Botín, Banco Santander’s Executive Chairman, said:

“One Pay FX uses blockchain-based technology to provide a fast, simple and secure way to transfer money internationally – offering value, transparency, and the trust and service customers expect from a bank like Santander. “From today, customers in the UK can use One Pay to transfer money across Europe and to the US. In Spain, customers can transfer to UK and US, while customers in Brazil and Poland can transfer to the UK.”

Each of the four countries the service is now available on offers customers different options depending on the market. For example, customers in Spain are able to send dollars to the USA and British pounds to the UK, while UK customers can send euros to 21 Euro-zone countries and dollars to the USA.

The service uses xCurrent technology from the privately-held Californian company Ripple. This payment solution allows banks to settle cross-border payments with end-to-end tracking. It is important to note that xCurrent does not use Ripple’s XRP token (unlike Ripple’s xRapid).

Santander’s debit card holders can access the One Pay FX service via online banking or mobile banking. In the latter case, iPhone-owning customers can use the bank’s “OnePay FX” mobile app, as long as their debit card has been registered with Apple Pay. Santander is not charging transaction fees for using OnePay FX, but says that it may do so in future.