Interchange fees for consumer credit cards were regulated by the EU in 2015 (http://europa.eu/rapid/press-release...16-2162_en.htm). For business cards the CC company still gets the higher interchange fee, that's why the business M&M CC still gets 1 mile per euro. AFAIU, the fee is based on the card issuer. So if you use a US card, the retailers bank (and the retailer in the end) has to pay the higher fee.