An investigation into the competitiveness of current accounts and small business banking has delayed the publication of its findings until August.
The Competition and Markets Authority first proposed the probe in July 2014 over fears that customers were not getting the best deal.
Difficulties switching current accounts, a lack of smaller competitors to the "big four" banks and lending to businesses were all areas for concern.
But the CMA has now delayed the publication fo its findings until August in order to "properly consider" responses to suggested measures to soften the impact of overdraft charges.
The CMA has said it wants banks to offer grace periods during which customers can take action to avoid unarranged overdraft charges. The CMA said banks should give customers a choice on whether they should have an unarranged overdraft facility or not and provide measures to limit maximum charges.
When the investigation was launched, the CMA said that overdraft charges were too complex and made it hard for customers to choose the cheapest or most appropriate accounts for them, which in turn limited the banks' incentives to compete.
Alex Chisholm, CMA chief executive, said in 2014:
"Competitive personal and SME banking markets are essential to households and businesses throughout the country, and to the success of the UK economy.
"However, our studies have found that despite some positive developments, significant competition concerns remain which mean that customers may not be getting consistently good service and value from their banks."
The CMA has said it welcomes responses to the overdraft inquiry by March 21.
