That $3.14 toll on a $100 card sale doesn't go to one company — it's sliced between an entire food chain. Here's who they are, what they actually do, and how each one gets paid.
When you tap a card it feels like the money jumps straight from you to the shop. It doesn't. Eight companies form a chain between your card and the shop's bank account, and each one takes a small cut for the part of the job it does.
On a $100 card sale the shop keeps roughly $97, and about $3 is split down that chain. The biggest slice goes to your own bank — the issuer — because it took the most risk. Meet the cast, see who keeps what, then see what happens when one link in the chain breaks.
Before you meet the cast, here's the loop they all live on. One click, one move — the message travels first, the money settles later, and every party takes a cut. Nothing moves until you press Next.
Tap any card to open it. The first four sit on the customer's side of the transaction; the rest fight for the merchant's side — that's where all the startups are.
The merchant's fee on a $100 credit sale, divided. Notice who gets the most — and who handles the most work for the least money.
The most-asked question in payments interviews. Think of getting paid like receiving mail:
"The mail slot in your door."
A secure front door for payment data. It encrypts the card number at checkout and carries it safely into the system. It doesn't move money — it moves messages. Sells for ~10–30¢ per transaction.
"The postal service."
The industrial plumbing that routes authorizations and settles funds between banks, millions of times a minute. Earns fractions of a cent each time — pure scale business. You've never heard of the biggest ones, and that's the point.
"The resident with a mailbox license."
A real bank that sponsors merchants into the card network and eats the risk if a merchant disappears owing refunds. Card networks only deal with banks — everyone else rents this relationship.
"The landlord subletting one big mailbox."
Holds one master merchant account and onboards you as a sub-merchant in minutes instead of weeks. In exchange, it keeps the whole blended spread (2.9% + 30¢ minus its costs). This is the Stripe/Square model.
Because modern fintechs are gateway + processor + PayFac at once — the bundle is the product. The unbundled version still exists underneath: somewhere behind every Stripe checkout, a sponsor bank (acquirer) and a network are doing what they did in 1985 — just invisibly.
These pairs sound interchangeable and aren't. Knowing the difference is how you spot who actually understands payments.
A chain is only as strong as its weakest party. When a link fails, the money and the blame land somewhere specific. Three real breaks, then a tree for tracing whose problem a stuck payment is.
Five questions about the chain behind every tap.
The industry's plumbing diagrams end where the P&L begins. This layer is the P&L.