Monzo is the UK's largest app-only bank. It started in 2015 as Mondo with a prepaid card, won a full banking licence in 2017, and grew mainly through word of mouth around features legacy banks lacked: instant notifications, spending categories, savings pots, bill splitting and fee-free card spending abroad. By March 2026 it had 15.2 million customers, which press reports describe as the seventh-largest UK bank by customer numbers. The company is headquartered in London, United Kingdom.
Monzo makes money in four main ways. First, net interest income: it earns interest on customer deposits placed with the Bank of England and on its loan book of personal loans, overdrafts and Monzo Flex credit. Second, subscriptions: customers pay monthly for Monzo Extra, Perks and Max plans, which bundle perks such as insurance and higher savings rates. Third, fees and interchange from card spending and paid Monzo Business plans. Fourth, smaller lines such as investments, pensions and partner products. The free personal current account acts as the acquisition engine; Monzo says most new customers arrive through word of mouth, which keeps marketing costs low.