The European Commission has launched an antitrust investigation to examine whether large players in Europe’s banking sector are prohibiting other companies from entering the online payments market.

As Reuters reports, banks including Deutsche Bank, HSBC, Banco Santander, Barclays Bank, Credit Agricole and Intesa Sanpaolo stand accused via a formal complaint to the European Commission, of blocking newcomers to the market through the practices of the European Payments Council, which wants to standardize the process for making e-payments within Europe.

The European Commission isn’t saying who filed the complaint, but argues that if new players not tied to European Payments Council member companies are blocked from entering the market, it could drive up prices for customers and merchants across Europe.