Lloyds Bank came in second, closely followed by Santander, in the evaluation which is based on Forrester's Website Functionality Benchmark methodology. With an overall score of 66, Barclays' site did well across a range of categories, with particular strengths in account management, money movement, security and login and electronic statement delivery. As a group, the eight secure websites of Barclays, Halifax, HSBC, Lloyds Bank, Nationwide Building Society, NatWest, Santander, and The Co-operative Bank scored a disappointing average of 54 out of 100 this year, and still lag behind those of the leading banks in the US and Canada.

"Each of the sites we reviewed in the UK does different things well, and our reviews uncovered many good practices that digital banking teams in the UK and elsewhere can learn from to plan for secure site upgrades in the future," writes Forrester Analyst Stephen Walker in his report.

Other key findings from the research include:

-- The majority of UK online adults (64%) now bank online — meaning they've viewed a balance, paid a bill, or transferred money online in the past three months.

-- Overall, UK banks scored strongly on money movement, supporting a range of transfers, payments, and bill pay, with helpful "add payee" and edit money movement options embedded into the task flow. Electronic statements are also strong, with most sites letting customers print and save statements going back at least 24 months.

-- Overall, UK banks fall short on money management, self-service, assisted service, and alerts. Lloyds Bank remains the only bank to offer effective money management. Few UK banks offer natural keyword search or secure messaging. There is also room for improvement around the breadth of possible alerts and web-to-branch guidance.