As the UK continues on its slow march to leave the European Union, a London-based startup that enables companies to work internationally has raised a huge round of funding from a strategic backer to expand its business. Ebury, which provides foreign exchange, money transfer and other currency services to small and medium businesses and their banking partners, has picked up £350 million (about €400 million, or $452 million) led by Spanish banking giant Santander. With the deal, Madrid-based Santander will become a majority shareholder at 50.1% but notes that Ebury will continue to operate as an independent entity.

Ebury and Santander said that the funding will be used to support Ebury’s growth, and specifically to scale its customer base in Latin America and Asia, while at the same time bolting on more modern services to Santander’s offerings as it seeks both to expand its revenues from existing customers and take on new ones.

Santander said that it has 4 million SME customers globally, and currently more than 200,000 of them do international business, while Ebury is already operating 19 countries and covers 140 currencies, with annual revenue growth of 40% in each of the last three years.

But putting to one side 4 million businesses, even providing services to 200,000 customers would be a big step up for Ebury: the company said that last year it processed £16.7 billion in payments for just 43,000 clients.

Santander said that its investment gives it a 50.1% stake in the company, but it is not disclosing total valuation. On a straight percentage, it would work out to about £700 million, or $902 million, but it sounds like the deal includes both primary and secondary investment — “£70 million will be new primary equity (approximately €80 million) to support Ebury’s plans to enter new markets in Latin America and Asia,” the companies note — and that could change the numbers. Santander is optimistic and said it expects a return on its invested capital in Eubury of higher than 25% in 2024.

Ebury’s existing investors and co-founders and management will also invest in the transaction. Past backers include 83North (formerly Greylock Israel) and Vitruvian Partners, among others. Founded in 2009, it has to date raised $134 million.

Services that Ebury currently provides include currency transfer and exchange, but it looks like there will be  more down the line. Just last month, Ebury announced that it had acquired another fintech called Frontierpay, which specialises in international payroll solutions. The deal is still going through regulatory approavals.

Many have lamented the fact that startups out of Europe find it hard to scale and grow and need to look to markets like the US for that kind of funding and support — often relocating in the process. Fintech is one of the big areas that bucks this trend.

Adyen built and still operates its successful online payments business out of the Netherlands; Revolut, Monzo and a wave of other so-called ‘challenger banks’ are revisiting what it means to provide banking services to consumers and businesses; and TransferWise — itself a major player in currency transfer services focusing both on individuals as well as businesses — are among the many that have scaled internationally out of Europe and have valuations in the billions.

Indeed, it’s competition from the likes of TransferWise that may have spurred Santander to invest in Ebury.

If bringing Ebury’s technology to the Santander platform will give the legacy bank a better way of competing in a market that’s seeing a lot of challengers at the moment, it also gives Ebury a stronger underpinning for those skeptical of doing business with a newer startup.

“Combining a big bank with nimble fintech means we can offer our clients the best of both worlds: they can benefit from our technology and high- quality service safe in the knowledge that they are counterparty to one of the world most important financial institutions,” said Juan Lobato and Salvador García, co-founders of Ebury, in a joint statement. “It is an exciting time for Ebury, we have just completed our first acquisition, and the new capital from Santander and our existing shareholders will allow us to invest in new ways to serve SMEs trading internationally and continue the growth in our business while keeping our entrepreneurial culture.”

Santander is not a stranger to making strategic investments in financial technology startups to grow its business, specifically by integrating or co-marketing those services alongside its own. It made an early strategic investment in Sweden’s iZettle, a Square competitor, that brought the startup into Latin America, and specifically as a co-provider of services to Santander’s customers in the region. Although it looked like iZettle could eventually get gobbled up by Santander, in the end, it was acquired by PayPal for $2.2 billion.

As with the iZettle investment, the focus for Santander here is on providing more services for SMEs, a huge sector that is fragmented and often overlooked and underserved against the bookends of mass-market consumer services and high-touch, high-end large enterprise services. The gap in turn becomes an opportunity.

“Small and medium-sized businesses are a major engine of growth around the world, creating new jobs and contributing up to 60% of total employment and up to 40% of national GDP in emerging economies,” said Ana Botín, Group Executive Chairman of Banco Santander, in a statement. “SMEs are becoming increasingly global and Santander is the best positioned bank to play a leading role to help them access global trade finance. By partnering with Ebury, Santander will deliver faster and more efficient products and services for SMEs, previously only accessible to larger corporates.”

Read more: