[hocuspocus]

The story is a little bit confusing.

Leaving the EEA, the interchange paid to debit and credit card* issuers is indeed not capped to respectively 0.2 and 0.3% anymore. Banks can decide to charge more, but that is not different from say, purchases with Swiss or US credit cards that happen in the EU. Merchants and payment processors have to deal with that. Whether they can pass on the fee to specific consumers, I believe that depends on countries and competition laws. The issue here is that the EU prohibits card payment surcharges, which makes MC and VISA very happy.

But back to the initial topic, what's MasterCard's real involvement in pushing for interchange increase? Their own fee isn't concerned by this cap anyway. And from what I understand, it's very small compared to the part going to payment processors. Why would they initiate the move? I'm sure banks are very well aware of regulations going away and opportunities to charge more fees.

* Only 4-party schemes, non-business/corporate cards.