Atom Bank CFO Andrew Marshall Appointed as Interim CEO

CEO of Newcastle- based Atom Bank, Mark Mullen, announces he has stepped down after just over a decade at the bank. 

After co-founding Britain’s digital-only lender with Anthony Thomson, Edward Twiddy and David McCarthy in 2014, Mark Mullen has steered the bank to become one of the most trusted, according to ratings on Trustpilot. 

To date, the bank has lent upwards of £5.8bn (US$7.86bn) to its clients. 

The move follows a failed sale of the bank after low offers earlier in the year.

As reported by the Financial Times, people familiar to the matter at Atom Bank say that shareholders would seek management changes which could include Mark Mullen if no purchaser emerged from a recent bid to buy the bank. 

The step up to CEO 

A senior in finance and strategy directives, Andrew Marshall has built a career over the last 20 years. 

Taking over from Co-Founder and ex-CFO David McCarthy in 2022, Andrew was described as outgoing CEO Mark Mullen as “extremely talented”. 

Andrew worked his way up the finance chain at Atom Bank, joining the neobank in 2016 as Group Financial Controller.

At the time of his appointment to CFO in 2022, Andrew said: “I am incredibly proud and excited to take this opportunity and to join the Atom board. We have built the foundations of a great business and I will now focus on accelerating our profitable growth for the benefit of all our stakeholders. 

“In such a volatile period, our mission to make the experience of borrowing and saving simpler, faster and better value is more important than ever.

“On a personal note, as someone who grew up in the North East of England, I share Atom’s passion for developing local talent and offering learning opportunities from our hub in Durham.”

Prior to his role at Atom Bank, Andrew spent five years at Barclays bank, where he moved after eight years at EY working in capital markets. 

Atom notes that Andrew has been “central” to the success and running of the bank. 

A farewell to Mark 

The bank delivered a strong FY 2025, with its results demonstrating the level of growth achieved by the neobank since it launched operations in 2016. 

Ending on a high note, Atom has grown to 550 people and operates on a four day work week thanks to Mark’s leadership. 

It contributes to the UK economy, having signed a Memorandum of Understanding (MoU) with Durham University to support important research and diversity initiatives. 

Operating profit reached £25m (US$33.88m), and the bank saw another uptake in customer numbers, up by 19%. 

Mark will advise the company until the end of the year to ensure maximum support is given to Atom Bank. 

The Board say they are grateful for “Mark’s significant contributions and the strong foundation he has established.”

Atom Bank partners: 

Thought Machine (2018): Led by CEO Paul Taylor, Thought Machine builds technology such as cloud-native core banking and payments technology for banks. Founded in 2014 in London, the company remains headquartered in the capital. Its product Vault Core is a complete core banking platform aimed at solving problems caused by banks running on legacy infrastructure. 

Assetz Capital: Founded in 2013 by Co-Founder and CEO Stuart Law, who has over 35 years of financial services experience, is a specialised property lending company. 

Durham University: Vice-Chancellor Professor Karen O’Brien runs Durham University. The University was founded in 1832 and is located in Durham. 

Codat (2020): Advisory intelligence platform Codat allows financial data to be turned into real-time insights. It is headquartered in London, UK, and is run by CEO and Co-Founder Peter Lord since its founding in 2017.