What Is a Card Network?
In payments, a card network is the company that operates the rails a card payment travels on and writes the rulebook that governs every transaction on it. That rulebook covers the dispute reason codes, the evidence you have to send, and the deadlines you have to meet. Visa, Mastercard, American Express, and Discover are the four networks in the US.
The network controls the part you feel as a merchant.
Your customer's bank issued their card and holds the account. So the network never touches the money side of a dispute. What it hands you is the code, the evidence bar, and the clock.
The four US card networks and how they differ
The four split two ways, because Visa and Mastercard put a separate bank behind every card while Amex and Discover usually issue their own. That one difference changes who you deal with when a customer disputes a charge.
Here are the four, and what each structure means for you:
- Visa: Open model, so a dispute pulls in your customer's bank, your bank, and Visa between them.
- Mastercard: Open model, same three-party dispute path as Visa.
- American Express: Closed model, so Amex is usually both network and bank, and it can contact you directly.
- Discover: Closed model, with the same one-party dispute path as Amex.
On an open network you never talk to the party that filed the dispute. Your bank gets it, you answer through them, and the network holds both banks to its rules.
The closed model describes the typical Amex or Discover card.
Both let other banks issue cards on their networks. A partner-issued card puts a separate bank back in the middle.
Summary: Visa and Mastercard put two banks in a dispute. Amex and Discover are usually both the network and the bank.
Card network vs. the other parties in a transaction
A card network only sets the rules, while the other four parties handle the money or the data. The issuer holds your customer's account, your acquirer holds yours, the processor moves the data, and the gateway captures it.
Merchants call all five "the processor." Only one of them holds your merchant agreement, and only one writes the dispute rules.
Five roles, one job each:
The two banks are the pair worth keeping straight, and our acquiring bank vs. issuing bank entry covers which one takes your call.
Gateway and processor split the same way. Our payment gateway entry walks through where checkout ends and processing starts.
What the network decides that a merchant feels
The network a transaction ran on sets the reason code, the evidence that counts, your response deadline, and the rate that triggers a monitoring program. Each one writes its own rulebook, and none of the four coordinates.
Four decisions, all theirs:
- The reason code: One complaint gets a different code per card.
- The evidence standard: What counts as proof differs, and so does what gets thrown out.
- The response window: The network sets your deadline, and your acquirer often shortens it.
- The monitoring threshold: Cross a network's dispute limit and it puts you in a chargeback monitoring program.
A Visa code means nothing on a Mastercard dispute. Read the one you were assigned:
Merchants who assume one shared limit get enrolled without warning. Visa calls a merchant Excessive at a 2.2% fraud-and-dispute ratio, dropping to 1.5% on April 1, 2026.
That Visa line applies in the US, Canada, the EU, and Asia-Pacific. Mastercard counts differently, running from 100 to 299 monthly chargebacks, or 1.5% to 2.99% of monthly transactions.
So read your chargeback rate one network at a time.
One cost sits outside all four. The network sets the interchange rate but never bills you for it.
Reason-code requirements differ by network, and our reason code lookup tool shows what each code covers.
FAQ
Is a card network the same as a card brand?
Both names point to the same companies, and merchants say "card brand" for the logo and "card network" for the rails underneath it. Apple Pay and PayPal ride on top of a card network, so a card still funds the payment and the network's rules still govern the dispute.
What is a card scheme?
A card scheme is the same thing as a card network, and the term is used more often outside the US, especially in Europe. Outside the US the roster is longer, and UnionPay and JCB are schemes on the same definition.
Do card networks set interchange fees?
Yes, the networks publish the interchange schedules, but they don't collect the money. Your acquiring bank pays interchange to the issuing bank, and you cover it inside your processing costs.
How do I find which network a card is on?
Check the first six to eight digits of the card number, which identify the issuer and the network. Our free bank identification number (BIN) lookup tool reads those digits for you.
