British telecoms regulator Ofcom has ordered BT to reimburse some of its corporate customers after it overcharged them for using its ethernet services.
BT is in dispute with five companies in three different cases over charges it imposed for using its high-speed data services.
The British telecoms operator may have to refund up to £94.8m to BSkyB, TalkTalk, Virgin Media, Verizon UK and Cable & Wireless.
"The parties were claiming that BT was charging too much and that its charges weren't cost orientated," said an Ofcom spokesman on Friday. "BT is required to orientate its charges to its own costs so it can't build in extra profit."
The first dispute came from Sky, TalkTalk and Virgin Media in July 2010, the second from Cable & Wireless in November 2011, and the third from Verizon UK in February 2012.
"We have found in favour of the parties that brought these disputes so BT is required to make repayments effectively of the extra amount of money they took," said the Ofcom spokesman.
"We are disappointed with Ofcom's determinations and refute the finding that we have overcharged for ethernet services," BT said in a statement. "We have provided evidence to Ofcom that shows we complied with our regulatory obligations and that we kept them informed of our pricing decisions throughout the period being disputed.
"We are considering all options available to us, including appealing."
BT has the opportunity to appeal the decision to the Competition and Consumer Tribunal before 21 February.