Of the half dozen recently formed "challenger banks" taking on incumbents in the U.K., Starling Bank may have the boldest strategy.

The mobile-first bank, which plans to open for business a year from now, hopes to set itself apart from the other half-dozen or so upstarts by focusing simply at first on its current account (the British version of a checking account). Led by Anne Boden, a 30-year veteran of the banking industry, Starling aims to build on the data it collects from customers to analyze patterns and make recommendations or add products.

The degree of success Starling Bank achieves could foreshadow how similar digital entrants in the United States might perform given a narrower product selection, a commitment to mobile, and a focus on collecting and analyzing data.

While industry observers point to the phenomenal growth of the mobile platform for traditional as well as upstart digital banks, account relationships are "sticky" in the U.K., as in the U.S., meaning customers are unmotivated to switch.

"Getting beyond customer apathy is a challenge for any new bank coming into the market," said Kieran Hines, practice leader for financial services technology at the research firm Ovum in London. "That may well be because consumers don't see enough out there to attract them to switch, and that's what is interesting about the entry of the challenger banks."

Almost two years after its founding, Starling Bank has raised more than £10 million (about $15 million) in capital. After a few bumps along the way, it is moving toward officially launching in mid- to late-2016 with a current account, a debit card, and potentially access to other payment offerings, all through a mobile device.

For CEO and founder Boden, a self-described technologist who left her job as chief operating officer for Allied Irish Banks PLC to lead this new foray into mobile-first financial services, the inception of Starling came as a result of "hearing what customers were demanding and seeing what the technology had changed."

In the United Kingdom perhaps even more than the United States, it's not just technology and a growing preference for the mobile channel that is sparking the rise of digital banks, but a new bank authorization process introduced there in March 2013. This lowered the initial capital and liquidity requirements for banking start-ups and makes it possible to have a "staged implementation," according to Boden. In other words, the bank team has been able to raise funds before all its licenses are in place, making it easier to launch.

Unlike rival Atom Bank, which has yet to launch as well, Starling also made the commitment early on to build much of its IT systems from scratch, rather than buy off-the-shelf software.

The bank is buying what Boden calls "commodity components for payments but also building a significant part of the bank ourselves. We're not buying a bank in a box."

When Starling Bank does introduce its offerings to British consumers a year from now, it will likely be entering a market for digital banking services that is becoming increasingly crowded with so-called challenger banks like Mondo (which would be similar to Moven or Simple in the United States) and mobile-first rival Atom, which applied earlier and already has a banking license. In an interesting twist, Tom Blomfield, Mondo's CEO, was the former chief technology officer and co-founder of Starling Bank, who left in February 2015 along with a handful of other executives from the fledgling Starling.

While the "mobile-first approach isn't new of course, Anne Boden has been vocal about Starling's aim to create a new customer experience in the banking space," said Hines.

Boden's plan for Starling calls for offering current accounts at scale through the mobile phone and collecting lots of personal and financial data to, in turn, analyze and help customers make better financial decisions.

"Time will tell if they are able to deliver on that of course," said Hines, "but the degree to which customers have embraced mobile banking in the U.K. certainly suggests that there is room in the market for this kind of proposition."

But just because the market is widening for these digital services in the United Kingdom does not mean that Starling Bank will be able to breeze into a British banking customer base.

According to Hines, the bank's purported plan to focus on providing current accounts and debit cards only, with other products sold via referral or partnership arrangements, could work for or against the emerging bank.

"If this [plan] enables Starling to become a gateway to best-of-breed products and preferential pricing, then this could work extremely well," Hines says. "However, the challenge here will be how to drive revenue. The cross-sale of banking products is traditionally a big revenue driver for established banks, and Starling's single product approach will require them to generate income differently. If monthly account or other fees are levied, this may hinder their ability to win new customers."

Karen Epper Hoffman is a freelance writer based in Olympia, Wash.