The European Court of Justice has upheld a ruling that fees charged by Mastercard were anti-competitive.
The court said regulators were right to condemn the cost of its interchange fees - the fees retailers pay banks to process card payments - and has rejected an appeal.
Mastercard was investigated last year for the amount it charged for card transactions in Europe.
The company's president said the ruling was "disappointing".
Javier Perez, president of MasterCard Europe said despite that, the ruling would have "little or no impact on how MasterCard operates".
He said: "We will continue to comply with the decision as we have been doing for a number of years. This means we would maintain our European... cross-border consumer interchange fees at a weighted average of 0.2% for debit and 0.3% for credit."
Mastercard is the second-largest credit and debit card company after Visa.
UK retailers welcomed the court's decision. Helen Dickinson, director general of the British Retail Consortium, said: "We are delighted with this historic ruling.
"Capping these excessive and anti-competitive fees will support the UK retail industry and others, boosting our ability to invest and innovate while continuing to deliver lower prices and value for customers."
The decision ends MasterCard's seven-year battle against a decision made by the EU's competition watchdog.