What is a scheme fee, and how is it different from interchange?
Interchange is the famous one. The scheme fee is the one that grew while nobody was looking at it.
Two of these are negotiated. One is set.
The three parts of what a card payment costs
The merchant sees one rate. Underneath it there are three components with three different destinations.
Interchange flows from the acquirer to the card issuer. It is the largest component in most markets and the most politically visible, which is why it has been capped in the EU and UK and set to zero for debit in India.
Scheme fees flow to Visa or Mastercard for operating the network, and are charged to both sides. They are not one fee but dozens: authorisation fees, clearing fees, settlement fees, cross-border fees, fees for the data services layered on top, and fees that depend on the transaction's characteristics in ways that are not always obvious in advance.
Acquirer margin is what your provider keeps, and it is the only part you genuinely negotiate.
Why scheme fees grew
Because the cap landed on the other one.
When regulators capped interchange, they addressed the transfer between banks. They did not address what the networks charge for the network. Total card acceptance cost fell less than the interchange reduction implied, and the scheme fee component grew as a share of the whole. Whether that is a market responding to a constraint or a system finding its level is a matter of interpretation. The direction is not in dispute.
The second reason is that the networks stopped being only networks. Tokenisation, fraud scoring, data services and dispute tooling are now scheme products with scheme pricing, and they are genuinely useful, which makes them genuinely difficult to decline.
What you can actually control
Not the rate. The behaviour that determines which rate applies.
Scheme and interchange pricing both vary by how a transaction is presented. A payment with full authentication data, correct merchant category, complete address information and a clean authorisation-to-capture sequence qualifies for better treatment than one missing those things. Fee optimisation in practice is mostly data hygiene wearing a commercial name.
The second lever is mix. Cross-border transactions cost materially more than domestic ones, and a transaction is cross-border on the basis of where the card was issued and where the merchant is registered, not where the customer is standing. Businesses selling internationally frequently discover that their entity structure is a pricing decision they made without knowing it.
The third is interchange-plus-plus pricing rather than blended. Blended pricing hides which component moved. You cannot optimise a number you cannot decompose.
A tenant's rent is capped by law. The service charge is not, and it covers the lifts, the lighting, the security and the new app for booking the meeting room. The rent stopped rising. The bill did not.
Where you meet it
Every merchant statement with a line you cannot explain. Every "we reduced your rate" conversation where the total bill did not move. Every business that expanded into a second country and watched its cost per transaction climb.
Building this? A second pair of eyes on the architecture is what the advisory is for. →