Accepting American Express as a merchant

The exclusion merchants rely on is narrower than it looks. Article 1(3) of Regulation (EU) 2015/751 puts transactions with cards issued by three party payment card schemes outside the interchange caps, which is the reason an Amex rate sits where it does.

Article 1(5) then takes much of it back. Where a three party scheme licenses other payment service providers to issue or acquire, or issues with a co-branding partner or through an agent, it is considered to be a four party payment card scheme. The transitional exemption that softened this for limited domestic schemes ran out on 9 December 2018.

So the honest answer to whether your Amex volume carries capped interchange is that it depends on how Amex operates in the market the card was issued in, and it is not the same answer everywhere. That is a question to put to whoever prices your Amex volume, and the answer changes what a fair rate looks like rather than being a piece of trivia.

Article 62(4) of PSD2 stops you charging for the use of a payment instrument whose interchange is regulated under the Interchange Fee Regulation. Three party schemes are outside that regulation, so they are outside the surcharging ban with it. American Express and Diners Club sit in that gap, and consumer Visa and Mastercard do not.

It is not a European yes. Article 62(5) allows each member state to prohibit or limit surcharging further, and several have done exactly that, so this is a national answer to establish per market rather than a right to assume. Where surcharging is available, it also has to be presented honestly at checkout, and the reputational cost of a surprise line is real.

The quieter right in the same article is usually worth more. Article 62(3) stops your provider preventing you from steering a customer towards a given instrument or offering a reduction for using it. Presentation order, default selection and a discount move payment mix without a customer ever seeing a penalty, and on a method with a rate this far above the rest that is where most of the recoverable margin sits.

Adyen, Checkout.com, Stripe, Global Payments, Nexi, Buckaroo and Datatrans all name American Express among the brands they accept, among others, as does effectively every European acquirer, so the question is the rate and the structure rather than the availability. Ask what your effective Amex rate is, whether you are on an aggregated or direct arrangement, and what your Amex volume and average order value actually are. That last figure is what gives you a negotiating position, and most merchants have never looked it up.