Now one challenger bank has proved it is possible to buck the trend, and the recent Brexit vote may have given it a nudge in the right direction.
OakNorth Bank today revealed it has broken even and inched into profitability, less than a year after it first began taking deposits and lending.
The specialist lender also waved away the sector's Brexit vote concerns by revealing it has closed over £100m in debt finance deals since 24 June and doubled its loan book to over £200m.
"I think [the Brexit vote] has actually played positively for us because fundamentally what happens is the larger banks slow down their rate of lending and, therefore, that just creates a further friction point for businesses," Rishi Khosla, chief executive and co-founder of OakNorth, told City A.M. "We have had situations where businesses have been in the last stages of getting approval and then the high street bank they've been working with has just gone mute on them."
OakNorth also announced today it was looking to expand its offering, with plans to launch various new retail products, such as instant access accounts and notice accounts. The first new product is due to launch next quarter.
Shares in listed challenger banks took a hefty knock following the Brexit vote, particularly after the Bank of England warned the smaller lenders would be less shielded from any downturn in the commercial property sector.
OakNorth itself is not currently listed and Khosla revealed there were no immediate plans for a float, although he added "who knows how far away that will be?"
The challengers were also dealt a fresh blow last month, as many slammed the Competition and Markets Authority when its long-awaited report did little to address red tape in the industry, focusing on how the sector was using technology instead.