Non-partner Amex's are considered "three party card schemes", and therefore not subject to the interchange caps [1]. This means that there's a chance your merc

Non-partner Amex's are considered "three party card schemes", and therefore not subject to the interchange caps [1]. This means that there's a chance your merchant has been paying more for each Amex payment. [1] https://curia.europa.eu/jcms/upload/docs/application/pdf/2018-02/cp180012en.pdf https://curia.europa.eu/jcms/upload/docs/application/pdf/201...