Follow the basis points: how interchange, scheme fees, and the four-party model decide who pays, who earns, and who sets the rules in every card transaction.
Payments Strategy Playbook covers commercial strategy. This goes deep on the single most important business model in payments: card and network economics, the part most practitioners are weakest on and where money is actually won or lost.
We decompose the merchant discount rate, follow interchange and scheme fees through the four-party model, model issuer economics, and read the networks as economic systems rather than logos, all the way to where the model is now under pressure.
Who the five roles actually are in a card transaction, how money and risk move between them, and why three-party schemes break the textbook diagram.
A single card payment is really three separate processes running on different clocks: authorization in seconds, clearing in hours, settlement in days. We trace the money and the messages through all three.
Interchange is the per-transaction fee an acquirer pays a card issuer, set by the network, and it is the single largest line in what a merchant pays to accept cards. This lesson covers what it is, who sets it, and the economic logic that keeps it in place.
Scheme and network fees are the cut Visa and Mastercard keep for running the rails, billed separately from interchange and made up of dozens of small line items most merchants never scrutinize.
How the merchant discount rate is built, why interchange-plus-plus pricing makes the cost stack legible, and how to read a processing statement well enough to catch what it hides.
The US, EU, and UK each regulate interchange differently, so the same card flow earns wildly different fees depending on geography. This lesson maps the three regimes and what they mean for the people who price and route payments.
Interchange gets the attention, but a credit card program is a lending business first. We break down the real revenue lines, what rewards cost, and why issuers court revolvers.
Who actually decides which network a debit transaction crosses, why merchants and issuers want opposite outcomes, and how Regulation II turned that fight into a structural feature of every US debit card.
The card networks endure not because they are cheap or technically superior, but because defaults, distribution, switching costs, and the two-sided cold-start problem make them very hard to dislodge. This lesson takes apart each mechanism and shows where it bends.
Account-to-account rails, pay-by-bank, and stablecoin settlement each attack a different layer of the card economics we built across this module. We separate the parts that genuinely route around the four-party model from the parts the networks have already absorbed.