The UK's Office of Fair Trading (OFT) has stated that the interchange fees charged by Visa's UK members for processing card transactions are anti-competitive.
The OFT has issued a statement of objections against Visa and its members, which includes most major banks, regarding the interchange fees that are applied to Visa card transactions in the UK.
The OFT says the collective interchange agreement between Visa and its member banks leads to an unduly high fee being paid to card issuing banks by merchant acquirers on every Visa transaction.
"The cost of these fees is passed on to retailers and ultimately to consumers," the OFT says.
The regulator claims the agreement restricts competition and infringes Article 81 of the EC Treaty and the Chapter I prohibition of the Competition Act.
In September this year the UK watchdog ruled that MasterCard's interchange fees infringed competition rules and led to higher retail prices. John Vickers, OFT chairman described the rules as "a tax on UK consumers".
MasterCard said it would appeal against the ruling and claimed the decision failed to recognise that interchange fees have contributed to expansion in the use of new technology and a more secure means of payment.