Most current account customers find it impossible to work out whether they are getting value for money, according to research.
Some 55% of people surveyed were unable to determine the value they are getting, a report, titled Current Account Switching - the Consumer Reality, which was published by Tesco Bank found.
A general lack of understanding of the charges and interest paid on an existing current account makes it harder for current account customers to move to another deal as they have "no effective basis for comparison", the report said.
The research looked at how likely people were to switch various types of financial product, including their car insurance, credit card, mobile phone and mortgage, as well as their current account.
Car insurance was the product that people were least likely to say they had not switched, with just 39% of consumers saying they had not done so.
This compared with 84% of consumers who had not changed their current account.
The only product that people were less likely to switch than their current account was their mortgage, with 85% of people not having done so.
While 6% of current account customers had switched their account in the last year, a further 9% said they had been considering switching and had actively researched their options, while 60% were not considering switching.
People who were not considering switching were more than twice as likely as switchers to say they could not work out the value of their current account.
The research also found nearly two-thirds (60%) of current account customers aged over 65 said they had held their main current account for more than 20 years.
The report was based on research among more than 1,000 current account holders.
Tesco Bank said it is releasing the findings to the Competition and Markets Authority (CMA). The bank is a relatively new challenger in the market, having launched its first current account in June 2014 with a promise to shake up the sector.
Benny Higgins, Tesco Bank chief executive, said more needs to be done to help current account customers understand the true cost and value of their accounts.
He said: "Only then will customers be able to secure a fair return on their money."
More than 1.1 million current account customers have switched their current account in the last year, according to figures recently released by Bacs, which is a 4% increase compared with the previous 12 months.
A new seven-day current account switching service was launched in autumn 2013, cutting the length of time it takes to switch from 30 working days.
All outgoing and incoming payments are automatically moved to the new account. Payments accidentally made to or requested from the old account are redirected to the new account for 36 months after the switch.
In further moves to make switching easier, earlier this year GoCompare launched a tool on its website which enables current account customers to see in pounds and pence how much better off they could be by switching provider.
The Government-backed "midata" tool aims to help consumers cut through the array of varied charges and benefits that come with current accounts so they can identify any potential savings.
People using the tool need to log on to their own online banking and click on the midata button to download 12 months of their statements on to a file. They then upload that information on to GoCompare's website.
Consumers can also tell the website who they currently bank with so they can see how their own provider appears in the rankings.
Economic Secretary to the Treasury Harriet Baldwin said: "The Government is committed to increasing competition in banking to improve outcomes for consumers: more competition means banks have to strive to offer the best possible products and services to their customers. I welcome this research from Tesco Bank which provides a valuable contribution to the debate."