Royal Bank of Scotland said the potential bill for claims against its small business restructuring division will remain at £400m after misconduct allegations against it were dismissed by Britain's financial regulator.
The UK's Financial Conduct Authority today published a detailed summary of a report into RBS' Global Restructuring Group (GRG).
Customers have accused the GRG of pushing ailing firms into bankruptcy to pick up their assets on the cheap.
The FCA last year effectively cleared RBS of the many of the allegations by customers.
The bank set up the £400m scheme to reimburse fees to customers who say they were mistreated.
The FCA's summary said the most serious allegations were not upheld in the report - reiterating findings from its "high level" summary published last year, the watchdog said in a statement.
The watchdog has rejected calls from British members of parliament to publish the full report that was undertaken by a "skilled person", in this case consultants Promontory.
The detailed summary reiterated that the full report has identified other concerns about the treatment of small firms.
"RBS has accepted that it did not meet the standards it set for itself which impacted on how it treated some of its SME customers," the FCA's chief executive Andrew Bailey said.
"We are investigating the matters arising from the Skilled Person's Report and are focusing on whether there is any basis for further action within our powers. We cannot comment any further on this," Bailey said.
The UK watchdog could take action against the bank or individuals.
RBS said it welcomed the FCA's confirmation that the most serious allegations have not been upheld, and that the steps it announced in November to put things right for customers remained appropriate.
RBS said it had completed the automatic refund of complex fees, with more than £115m of refund offers made.
It said it continued to estimate the cumulative cost of these measures to be about £400m.
"The culture, structure and way RBS operates today have all changed fundamentally since the period under review," the bank's chief executive Ross McEwan said.
The UK parliament's Treasury Select Committee has hired a barrister to check whether the detailed summary published is faithful to the full report.
The FCA said a final version of the detailed summary would be published once the Committee's barrister has reported back.
Treasury Committee Chair Nicky Morgan said today it had taken the watchdog too long to publish the detailed summary.
"When its independent adviser reports back later this week, the Committee will consider whether further steps are required," Morgan said.
Bailey is due to be questioned on the report into RBS by the UK Treasury Committee on October 31.
