Britain’s competition watchdog CMA has launched investigation into services offered by the country’s big four banks to small business customers and personal accounts because of a lack of competition.
HSBC and Barclays as well as bailed-out lenders RBS and Lloyds Banking Group will face a formal investigation.
"After carefully considering the consultation responses, most of which supported a market investigation, we remain of the view that there should be a full market investigation into the sector," said Alex Chisholm, chief executive of the Competition and Markets Authority (CMA).
"Effective competition in retail banking is critically important for individual bank customers, small and medium-sized businesses, and the wider economy," Chisholm added.
The investigation, which may take until May 2016 to complete, had been expected after the CMA said in July a full probe was on the cards.
As part of the probe, CMA will investigate difficulties faced by customers in switching banks, lack of smaller competitors to the big four banks, and lending to businesses.

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By GlobalDataPotential outcomes of the probe could include breakup of the biggest banks, demand for more fee transparency, and split of branch networks.