Leading banks in the UK, by number of customers 2023

The UK-based bank with the highest number of customers in 2023 was Santander, with over 164 million customers worldwide. Barclays followed, with a global customer base of 48 million. Despite their high customer numbers, both these banks rank relatively low when it comes to current account holder customer satisfaction. The top three banks in terms of satisfied customers as of August 2023 were the online banks Starling Bank, First Direct, and Monzo Bank. 

Are customers switching to online banks?

Many current account holders in the United Kingdom switch provider each month. In 2020 and 2021, it seemed like the switches came from the larger banks with many customers to the smaller, more newly founded online banks. The two online banks Starling and Monzo generally have high numbers of net gains for customers, but as of the second quarter of 2023, HSBC and NatWest saw the highest net gains. 

Complaints of UK bank customers

Despite its high worldwide customer number, HSBC seems to have a hard time satisfying its domestic customers in the United Kingdom. In the first half of 2023, HSBC had the second-highest number of banking and credit cards services complaints opened among the domestic banks in the UK.