Monzo has announced it will cease operations in the United States, a move the digital bank has described as "deliberate" and "strategic".
The withdrawal will result in approximately 50 redundancies among US-based staff.
New customer sign-ups in America have already been halted, though current account holders will retain access to their services until June.
The digital bank described as "deliberate" and "strategic" as it pivots towards growth opportunities in Britain and across Europe.
A company spokeswoman stated: "With a fast-growing customer base of 15 million in the UK and the growth opportunity our European banking licence creates, we're making a deliberate, strategic decision to focus on scaling in our home market and Europe and to step away from the US."
The challenger bank has experienced remarkable expansion since its 2015 launch, establishing itself as a formidable rival to traditional high street lenders.
Its customer numbers have now surpassed 15 million, securing its position as Britain's biggest digital-only bank and ranking seventh nationally by total customers.
Monzo to exit US
| GETTYEuropean expansion is already underway following the acquisition of an EU banking licence last year.
Ireland has become the company's inaugural market on the continent, with services now available to consumers there.
The spokeswoman added: "We're very grateful to our US colleagues and customers for their support and love for Monzo."
Major UK Bank to exit US in 'strategic' move that will cut 50 jobs
| PAMonzo's American venture never gained significant traction, with the company operating a modest service offering debit cards, savings features and app-based tools.
The firm abandoned its US banking licence application in 2021 after receiving indications that approval was unlikely.
Despite recruiting fresh leadership in 2023 with hopes of reinvigorating its American ambitions, the market proved too challenging to crack.
The US exit represents a significant strategic shift under Diana Layfield, who assumed the chief executive role in February.
The former Google general manager took over from TS Anil, who departed following five years leading the company.
He stated that he believes "great leaders make way for others".