Revolut racked up twice as many complaints as its nearest rival Monzo.
Revolut amassed more customer complaints than any other major full-service digital bank operating in the UK between 2015 and 2018, according to a Freedom of Information request.
The banking app received 171 claims from British customers that were taken up by the Financial Ombudsman Service over this period, said the Financial Times.
By comparison, rival Monzo drew 82 complaints in the same period.
Rival Starling Bank, which launched in 2017 and has around 600,000 customers, received 51 complaints during this period, according to Financial Ombudsman Service data.
Fellow challenger bank Tandem, which has a similar number of customers, has been the subject of 30 claims since it launched in early 2018.
The Financial Ombudsman Service, set up by parliament, is tasked with settling disputes between consumers and businesses and financial service firms, such as banks and insurance companies. The body usually steps in when issues cannot be resolved through the financial firm’s internal complaints procedure.
Revolut recently said it will introduce a phone line to help improve its customer service, following criticism on social media that urgent requests for help, for such issues as frozen accounts, were met with slow responses.
Also, this year Revolut has faced scrutiny from British regulator Financial Conduct Authority, the UK Advertising Standards Authority and the Lithuanian parliament, where the bank received its banking licence.
Most fintech banks are loss-making but are racing to add accounts, which they later hope to turn into profitable customers. These firms continue to attract billions from investors who believe this wave of companies can emulate Big Tech giants such as Facebook and Google.
But consumer groups warn that these banks must not sacrifice customer service levels as they chase growth. Gareth Evans, co-director of the Financial Inclusion Centre, a consumer rights group said: “As these shiny new fintech firms become more prominent, it’s important to take note of any early warning signs.”
A spokesman for Revolut said: “Having been operational for longer than our competitors, we would expect to experience some complaints. While our current rate of complaints is very low proportionate to our customer base, we are fully committed to continually improving our services and will always do all we can to ensure our customers have no reason to complain.”
Tandem bank’s chief people officer Dan Atkinson added: “By taking criticism on board, we strive to build a better kind of bank.”
However, complaints received by digital banks paled in comparison to established high-street banks, such as Barclays and Lloyds Bank, who each received more than 100,000 complaints during the period.