Monzo has grown rapidly since it was founded in 2015, attaining its banking license in 2017. It took three years for the online banking platform to reach 600,000 users and by 2022 was closing in on six million. By April 2025 the bank had more than 12m Monzo clients.

However, with such rapid growth the bank faced a heightened risk of dealing with an increasing number of people who were considered high risk and also let duplicate accounts slip through the vetting process due to a ‘lack of effective onboarding controls’.

Two separate individuals who had previously had their accounts closed due to financial crime concerns managed to open new accounts multiple times.