Profits of Britain’s biggest banks at risk from AI-driven customer cash shifts

By the Editorial Team · Wednesday, September 16, 2026

AI-powered financial tools are encouraging UK consumers to move up to £700 billion from low-interest current accounts to higher-yield savings products, which could reduce banks’ net interest margins and profits on deposit funds by over 20%. This shift threatens traditional revenue models for the largest UK banks and accelerates competition from fintech challengers like Monzo and Revolut, prompting potential regulatory responses such as a bank windfall tax.

Profits at Britain’s largest banks could face significant pressure as artificial intelligence-driven tools encourage consumers to move cash from low or zero-interest current accounts into higher-yield savings products. According to consultancy firm McKinsey, AI chatbots and digital assistants may prompt savers to shift up to £700 billion into accounts offering better returns, potentially reducing banks’ revenues derived from current account deposits.

Banks have traditionally profited from the difference between the negligible interest paid on customers’ current accounts and the higher rates charged on loans, a key source of income known as the net interest margin. The accumulated deposits held in current accounts—often paying no interest—have funded lending activities, generating substantial earnings for lenders. However, the rise of AI-powered financial tools could disrupt this model by swiftly identifying and facilitating transfers of idle balances into more lucrative savings options.

McKinsey highlighted that UK consumers tend to hold a significant portion of their wealth in cash rather than investments, with approximately seven million adults possessing investable assets of £10,000 or more held entirely in cash. AI-driven digital agents have the potential to alter these savings patterns by automating the comparison and reallocation of funds to higher-yield products. The consultancy estimates that if only 5 to 10 percent of deposits were redirected this way, bank profits on deposit funds could decline by 20 percent or more.

The "big four" UK high-street banks reported combined profits of £29.2 billion in the first half of 2026, a 21 percent increase compared to the previous year. Meanwhile, Chancellor John Healey is reportedly contemplating a windfall tax on bank profits in the forthcoming Budget.

AI adoption is widespread among UK consumers, with over half already using AI tools and around one-quarter relying on such technology for financial tasks monthly. Usage is even higher among affluent customers. McKinsey noted that more users seek financial advice from general AI platforms like ChatGPT and Google’s Gemini than from banks’ proprietary chatbots.

In this evolving landscape, challenger banks such as Monzo and Revolut have leveraged AI to expand their customer bases and compete with traditional lenders. These fintech firms, often operating with leaner staffing models, have rapidly attracted tens of millions of users. For instance, Revolut nearly tripled its customers between 2022 and 2025 while reducing its cost per customer by £3. Though many consumers still receive their salaries via established high-street banks, they increasingly turn to fintech platforms for everyday spending and financial management.

The growing integration of AI into personal finance represents a transformative shift in consumer behavior that could reshape revenue streams for traditional UK banks, prompting a reassessment of business strategies amid intensifying competition from technology-driven financial services.

This article was reported by synthesizing coverage from multiple independent news outlets to present a balanced, unbiased account. Read about our editorial standards. Spotted an error? Let us know.