First Direct has topped a customer satisfaction index for the 10th year in a row.
The latest UK Customer Satisfaction Index (UKCSI) revealed First Direct was the highest scoring organisation in the banking sector, with a score of 86.1.
First Direct has consistently scored above 80 since January 2008, as has Nationwide since January 2011.
Yorkshire Bank was the most improved organisation with a score 10 points higher than in January 2017.
Jo Causon, chief executive of The Institute of Customer Service, which published the data, said while customer satisfaction within the banks and building societies was steadily improving, this sector still faced a tough road ahead.
She said: "With the rise of technology and many service roles becoming automated, it is vital that providers work with new technology to ensure a differentiated and seamless user experience.
"The temptation may be to hold back amidst an uncertain economic climate, but with improvements in customer service worth £81.5bn to the UK’s GDP through repeat custom and recommendation, consistency is key to success.
"It is also clear that where satisfaction is maintained, organisations will see a direct link to turnover growth, profitability and productivity."
The UKCSI also revealed banks and building societies were the fifth highest scoring sector for customer satisfaction with a UKCSI score of 79.8.
The sector now scores 1.7 points higher than the UK all-sector average of 78.1 and is 1.1 points above the insurance sector.
Between January 2017 and 2018, the average UKCSI score for banks and building societies improved by 0.3 points.
The UKCSI revealed customers are most satisfied with the customer service on their personal loan, which scored 81.7 points. This was followed by their current account, which scored 80.5 points and credit card, which scored 79.5 points.
The lowest scoring product was mortgages at 74.4 points.
Julie Lord, chief executive and chartered financial planner at Bridgend-based Magenta Financial Planning, said: "I think most consumers are prepared to pay a premium for a premium service if it actually delivers a better service.
"Consumers should be aware that many banks charge for extra services, for example, travel insurance, motor recovery and mobile phone cover, when in fact the customer never uses these services or pays for them separately."