Co-badging
A card carrying two card networks at once, usually one domestic and one international, and the fight over who gets to pick which one runs the payment.
The model thrives wherever a strong domestic scheme exists. French cards carry Cartes Bancaires plus Visa or Mastercard, German ones girocard plus an international brand, Danish ones Dankort plus Visa. At home the payment goes through the cheaper local network, abroad through the international one. It is also a survival strategy: without co-badging, customers would pick cards based on what works on holiday.
The real argument is about choice. The EU's 2015 Interchange Fee Regulation lets merchants set which network the terminal prefers, but the cardholder can override it. In the US, the Durbin Amendment requires every debit card to be routable over at least two unaffiliated networks, and a 2023 clarification extended that to online payments. Visa and Mastercard have long done their best to make sure it is their logo that wins.