What is a card network? A merchant's guide and list

A card network is the company that runs a card brand's payment system. It writes the rules, carries each sale's authorization and clearing messages between the banks involved, and charges for the service. When a customer taps a Visa card at your counter, Visa isn't the one lending them the money or paying you. Its job is the system in the middle.

Visa put it bluntly in its 10-K for fiscal 2016: it isn't a bank, and it doesn't issue cards, extend credit or set rates and fees for account holders (Visa). Banks do those things. That split, between the network and the banks on each side of a sale, explains most of what lands on your statement.

The credit card payment networks you'll meet in the US are Visa, Mastercard, American Express and Discover, with debit networks such as STAR alongside them, and Interac in Canada. Network facts in this guide were checked on October 11, 2026.

What does a card network do?

It does four jobs on every sale, though the only part your customer sees is the logo.

1. It writes the rules. Each network sets operating rules for the banks that issue and acquire its cards. Visa's annual filing for fiscal 2017 says its financial institution clients are responsible for managing account holder and merchant relationships (Visa), so the rules reach you through your acquirer rather than a contract with Visa.
2. It carries the messages. In Visa's own description, a merchant hands transaction data to an acquirer, usually a bank or third-party processing firm, and the acquirer passes it to Visa through VisaNet (Visa). The network routes the authorization request to the card's issuer and carries the answer back.
3. It sets interchange. Mastercard says it establishes its interchange rates and that acquirers generally pay them to card issuers on purchases (Mastercard). Visa's fiscal 2018 filing calls interchange a transfer of value between the financial institutions in its open-loop payments network, money Visa collects and passes along but generally doesn't keep (Visa).
4. It charges its own fees. In its 10-K for fiscal 2025, Visa says it sets its fees to acquirers independently of any fees acquirers charge sellers, and that acquirers set the merchant discount fees sellers pay (Visa).

Here's how that plays out on a $90 sale at a bike shop in Omaha, paid with a Visa credit card:

1. The customer taps, and the terminal sends an authorization request to the shop's processor.
2. The request goes into VisaNet, which routes it to the bank that issued the card.
3. The issuer approves, and the answer travels back the same way in a few seconds.
4. That evening, the shop's batch goes through clearing. In Visa's description of settlement, the issuer effectively pays the acquirer the sale amount minus interchange (Visa).
5. The acquiring side pays the shop what's left, minus Visa's network fees and its own markup.

Credit card networks vs issuers: who does what?

The issuer is your customer's bank, and the network is the system its card runs on. Your acquiring bank and your processor sit on your side of the sale. The four roles split like this:

Two quick tests keep them straight. Look at the card: the network's logo usually sits next to the issuer's name. Then follow the money: interchange goes from your acquirer to the issuer, while the network collects its own, separate fees. Visa's filing for fiscal 2021 adds that it doesn't earn revenue from, or bear credit risk on, the lending and account fees its issuers handle (Visa). The interest your customer pays goes to their bank.

Our guides to the issuing bank and the acquiring bank cover each side in depth. Clearo provides payment processing and merchant accounts on interchange-plus pricing, so interchange, network fees and our markup each get their own line on your statement.

Credit card networks list for US and Canadian merchants

Here's the list of credit card networks, and the debit networks beside them, that a business in the US or Canada is likely to see:

The schedules are Visa's US interchange reimbursement fees and Mastercard's 2026-2027 US rates. Each brand has its own merchant guide on our blog: Visa interchange rates, Mastercard interchange rates and American Express merchant fees.

Discover's ownership in 2026

Discover changed hands recently, so here's where it stood when we checked on October 11, 2026. The Federal Reserve approved Capital One's application to merge with Discover Financial Services on April 18, 2025, and at the same time issued a consent order with Discover that included a $100 million fine for overcharging certain interchange fees from 2007 through 2023 (Federal Reserve). Capital One says it completed the acquisition on May 18, 2025 (Capital One). If you accept Discover, ask your processor whether anything about your Discover acceptance or pricing is changing, and check the Discover lines on your next statement.

Debit networks in the US

Debit cards come with a choice of networks built in. The Federal Reserve's debit data lists Visa and Mastercard alongside networks such as Interlink, Maestro and STAR (Federal Reserve). Its Regulation II requires every debit card to be enabled on at least two unaffiliated networks, and it bars issuers and networks from blocking the merchant's choice of route (Federal Reserve). Your processor usually makes that choice sale by sale; our guide to least cost routing explains how to check it works in your favor, and our guide to the Credit Card Competition Act covers a bill that would bring routing choice to some credit cards.

Card networks in Canada

In Canada, FCAC names the major payment card network operators that have committed to the Code of Conduct for the Payment Card Industry: American Express Canada, Discover, Interac, Mastercard Canada, Visa Canada and UnionPay (FCAC). Interac is the outlier on pricing. Interac Debit lets customers pay directly from their bank account (Interac). Interac says it carries a single flat fee regardless of purchase price, at around 10 cents a transaction (Interac), and it promises merchants zero chargebacks (Interac). Our guide to what Interac is compares it with credit.

JCB and UnionPay

Two global networks round out the list. EMVCo, the body that manages the chip card specifications, is collectively owned by American Express, Discover, JCB, Mastercard, UnionPay and Visa (EMVCo), and UnionPay is on FCAC's Canadian list above.

Open-loop vs closed-loop card networks

An open-loop network sits between separate issuers and acquirers. A closed-loop network handles both ends itself.

Visa is the standard open loop. Banks issue its cards, other banks sign up merchants, and Visa's annual report calls the result its open-loop payments network. Mastercard works on the same split, with interchange flowing from acquirers to the issuers of its cards.

American Express is the classic closed loop. Its 2025 annual report describes card-issuing, merchant-acquiring and card network businesses within one company (American Express). Its 10-K for 2019 explained the payoff: direct relationships with card members as an issuer and with merchants as an acquirer create a "closed loop," with direct access to information at both ends of a card transaction (American Express).

The loop has openings, though. In its 10-K for 2017, Amex described cards issued by third-party banks through its Global Network Services business: when one of those cards is used at a merchant Amex acquires, Amex pays the merchant and, as network operator, receives settlement from the partner issuer (American Express). On the merchant side, OptBlue lets eligible small businesses accept Amex through their payment provider, which sets their Amex rate (American Express).

Amex publishes Merchant Regulations for businesses that accept directly, and its Merchant Operating Guide is written for merchants signed through a provider. Why the design matters to you: Visa and Mastercard interchange is published and the same whichever processor you use, so you compare processors on markup. Under OptBlue, your provider sets the whole Amex rate, so ask for it as a separate line. Our guide to Amex OptBlue covers how that price is built.

What do card networks cost a merchant?

Networks don't take a cut of interchange; they bill their own fees on top. So each card sale carries three layers: interchange for the issuer, network fees for the network and your processor's markup. Mastercard calls interchange only one of many cost components in a merchant discount rate, and says it has no involvement in acquirer and merchant pricing (Mastercard).

The network's schedule sets the biggest layer, and the card your customer picks decides which line of it applies. Take a $250 sale, dipped at a furniture store in Nashville:

The debit row is the Federal Reserve's Regulation II cap (Federal Reserve); the credit rows are Visa's card-present rates effective April 18, 2026 (Visa). Same store, same $250, and interchange runs from about 35 cents to $5.35, depending on what the customer pulls from their wallet. Visa's network fees and your processor's markup sit on top of every row.

Network schedules move, too. Mastercard says its interchange rates are typically updated twice a year (Mastercard), so compare statements from before and after each update. On interchange-plus pricing, each layer shows up separately, which is what makes that comparison possible. Our guide to what interchange fees are goes line by line.

How do card network rules reach your business?

Through your acquirer and your merchant agreement. You usually won't sign anything with Visa or Mastercard directly, but their rules shape what you can charge, how you take cards and how disputes end.

On category, Visa makes the acquirer responsible for assigning the correct merchant category code to each merchant (Visa), and that code affects which interchange rates your sales can qualify for.

Surcharging rules in the US and Canada

In the US, Visa caps a credit card surcharge at the lower of your merchant discount rate or 3% and asks for 30 days' notice to your acquirer (Visa). Mastercard's limit is the lower of your average effective merchant discount rate or 4% (Mastercard). Neither network lets you surcharge debit or prepaid cards. American Express writes its own rule: its Merchant Operating Guide bars fees on Amex cards that aren't applied equally to other payment products, with exceptions for electronic funds transfer, cash and check (American Express).

Canada has its own numbers. Visa Canada allows a credit surcharge up to your merchant discount rate, with an absolute cap of 2.4% (Visa Canada), and Mastercard's Canadian cap is also 2.4% (Mastercard). FCAC tells merchants they can add a surcharge to a credit card transaction except in Quebec (FCAC). Interac's fee rules cap any surcharge fee on Interac Debit at $0.25 and say merchants may not apply one directly (Interac).

Dispute rules

Visa defines a dispute as the reversal of a transaction's value by the issuer to the acquirer (Visa), and each network sets its own deadlines. Mastercard's chargeback guide, for one, lets some service disputes be filed within 120 calendar days of when the service ended, with 540 days as the outer limit (Mastercard).

Rule changes still pending

Visa's proposed settlement of the US merchant class action over interchange includes changes to surcharging and honor-all-cards rules (Visa), and the court's June 9, 2026 preliminary approval isn't final approval (Visa), so none of those changes apply yet.

Which card networks should your business accept?

Take the networks your customers carry, then check what each one costs you. A sensible order:

1. Visa, Mastercard and debit. They're the baseline wherever you sell. In Canada, add Interac Debit.
2. American Express. Amex says its cards can be accepted at 99% of places in the US that accept credit cards (American Express), so customers who carry one expect to use it. Price it through OptBlue or directly with Amex, then compare.
3. Discover and the rest. Confirm your processor's terms, and count how often customers ask for a brand before you add it.

Clearo's POS terminals read chip, tap and swipe and accept Interac, Visa, Mastercard, Apple Pay and Google Pay.

Next step

Your statement already shows what each network costs you, as long as it's itemized. Send a recent one for a free statement review, and we'll separate interchange, network fees and markup for every brand you accept, so you can see what Visa, Mastercard, Amex and Discover each cost. Prefer to talk first? Contact us.