Atom Bank to replace veteran chief who advocated four-day working week

The veteran who has run Atom Bank, Britain's first digital-only lender, is to step down just two months after an auction of the business failed to attract offers at an adequate level.

Sky News has learnt that Mark Mullen, who has been at Atom Bank since 2014, is to relinquish his role in the coming weeks.

Sources said that Mr Mullen was expected to be replaced on an interim basis by Andrew Marshall, the company's chief financial officer.

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The change of leadership at the app-based bank will come amid uncertainty over its future ownership in the wake of an auction which was abandoned in June.

Atom Bank had been working with advisers at Jefferies on a sale process which investors hoped would value it at anywhere between £600m and £1bn.

The process failed to elicit firm bids despite tentative interest being shown by several private equity firms and at least two building societies.

Founded in 2016 and headquartered in Newcastle, Atom Bank has about 250,000 customers and has built a substantial presence in the mortgage and savings markets.

It was set up as Britain's first digital-only bank by Anthony Thomson, the co-founder of Metro Bank and one of the UK's most prominent financial services entrepreneurs.

Mr Thomson has since embarked on a number of other ventures in the sector, and has most recently been raising funds for a new Jersey-based business called Velorai, aimed at wealthy families.

Since he left Atom Bank in 2018, its performance has consistently lagged that of rival 'neobanks' which launched in the decade after the 2008 financial crisis, such as Monzo, Zopa and Starling Bank.

Atom Bank, which employs about 600 people, has raised capital from investors on a number of occasions since it was founded, with the most recent fundraisings described as pre-IPO rounds as it prepared to list its shares publicly.

Its major shareholders are the Spanish banking giant BBVA, Toscafund and Infinity Investment Partners, a London-based investment firm.

Neil Woodford, the now-disgraced former fund manager, was previously a shareholder in the company through Woodford Investment Management.

The company also has a number of smaller shareholders, including Lexham Partners, another UK-based investor.

Atom Bank has been in talks with regulators for some time about being allowed to adopt a more capital-efficient Internal Ratings-Based model, with work on this understood to be continuing.

Investors hope that regulatory approval for the switch to an IRB model will be transformational for the company's valuation.

In 2021, Atom Bank began allowing employees to work a four-day week, becoming one of the biggest UK companies to embark on such a radical shift in its working practices.

Mr Mullen, a former boss of HSBC subsidiary First Direct, has also been an advocate of Atom Bank's low-carbon credentials, announcing in 2024 that it had purchased 25 acres of woodland in Northumberland as it targeted becoming "a climate-positive bank" by 2035.

Its new Newcastle headquarters were opened last year by Lucy Rigby, the City minister.

Atom Bank initially said it would respond to enquiries from Sky News but then refused to answer further calls when pressed for comment.

(c) Sky News 2026: Atom Bank to replace veteran chief who advocated four-day working week