A payment network is the infrastructure that routes an electronic payment between your bank and the business you’re paying. When you tap a card at a coffee shop, companies like Visa or Mastercard carry the transaction data from the merchant’s bank to yours, apply a shared set of rules, and make sure the money ends up in the right place. Visa and Mastercard alone handled nearly $10 trillion in U.S. card purchases in 2025.1Nilson Report. Mastercard and Visa Cards in the US 2025 The network itself doesn’t issue your card or hold your money. It’s the connective tissue that lets a card from a small credit union work at a shop halfway around the world, without either bank needing a direct relationship with the other.
Who Is Involved in a Card Payment
Five separate parties touch every card transaction. Once you can name them, the rest of the process makes sense.
- The cardholder is you, the person paying.
- The merchant is the business selling to you. Its terminal or checkout page captures your card data and starts the payment request.
- The acquirer is the merchant’s bank. It collects the merchant’s transactions and submits them to the network.
- The network is the routing and rules system, such as Visa or Mastercard. It moves data between the acquirer and the issuer and sets the standards everyone follows.
- The issuer is your bank or credit union. It gave you the card, approves or declines each purchase, and carries the primary risk if you don’t pay or if fraud occurs.
The merchant never talks directly to your bank. The acquirer hands the transaction to the network, the network routes it to your issuer, and the answer travels back along the same path. That’s why a card issued by a tiny local bank can work anywhere in the world: the network bridges two institutions that have no direct connection and guarantees the merchant will get paid if your issuer approves the charge.
How a Card Transaction Actually Moves
Every card purchase goes through three phases. The first happens in the second you’re standing at the counter. The other two run in the background over the next one to three business days.
Authorization
The moment you tap, dip, or swipe, the merchant’s terminal sends an encrypted request through the acquirer to the network, which routes it to your issuer. Your issuer checks whether your account is active, whether you have the funds or credit available, and whether the transaction looks fraudulent. Modern authorization typically completes in well under a second.
If the issuer approves, it sends back an authorization code and places a hold on the funds. No money has moved yet. The hold just reserves the amount so you can’t spend it twice. The merchant sees the approval and hands over the goods.
Clearing
At the end of the business day, the merchant sends its approved transactions to the acquirer in a single batch. The acquirer forwards them to the network, which sorts each one and routes the final details to the correct issuer. This is where a preliminary authorization becomes a formal financial obligation.
Clearing is also where estimated amounts become final. If you paid at a gas pump or added a tip at a restaurant, the actual charge is locked in during this step.
Settlement
Settlement is when money changes hands. The network calculates the net amounts owed between all the issuers and acquirers in its system and moves the difference instead of processing each transaction individually. Your issuer transfers the transaction amount, minus an interchange fee, to the merchant’s acquirer. The acquirer deducts its own processing fee and deposits the rest into the merchant’s account.
Most domestic transactions settle in one to three business days. Cross-border purchases take longer because of currency conversion and extra compliance checks.
Open Loop and Closed Loop Networks
Card networks fall into two structural camps, and the difference shapes how the card in your wallet works.
Open Loop Networks
Visa and Mastercard are open loop networks. The network itself doesn’t issue cards or hold consumer accounts. It’s purely a routing and rules system, and any bank that meets its certification standards can issue cards or sign up merchants under its brand. That structure creates competition: thousands of banks compete to offer Visa or Mastercard products, which is why cards carry different rewards, rates, and features even though they run on the same rails. Visa held about 70% of combined Visa-Mastercard U.S. purchase volume in 2025.1Nilson Report. Mastercard and Visa Cards in the US 2025
Closed Loop Networks
American Express and Discover historically operated as closed loop networks. The same company issued the card, processed the transaction, and managed the merchant relationship. That gave them tighter control over the customer experience and richer transaction data but a smaller merchant footprint, because every merchant had to contract directly with the network. Both companies have since licensed other banks to issue their cards, so the line between open and closed loop has blurred.
Networks That Aren’t Card Networks
Not every electronic payment runs on a card network. Two other systems handle enormous volumes of non-card transfers in the United States, and it’s worth knowing they exist so you don’t confuse them with what happens when you swipe.
The ACH Network
The Automated Clearing House network moves money between U.S. bank accounts for payroll direct deposits, bill payments, tax refunds, and peer-to-peer transfers. In 2025, ACH processed 35.19 billion payments totaling $93 trillion.2Nacha. ACH Network Volume and Value Statistics Roughly 80% of ACH payments settle in one business day or less.3Nacha. The Significant Majority of ACH Payments Settle in One Business Day or Less ACH fees are a fraction of card interchange costs, which is why employers, utilities, and government agencies rely on it so heavily.
FedNow and Real-Time Payments
The Federal Reserve launched its FedNow Service on July 20, 2023, creating a real-time payment rail that operates around the clock every day of the year.4Board of Governors of the Federal Reserve System. FedNow Service Unlike ACH, which processes in batches, FedNow settles each payment individually and instantly. The money arrives in seconds with finality; there’s no pending period, and the sender can’t claw it back. The private sector’s Real-Time Payments (RTP) network, operated by The Clearing House, offers similar instant settlement.
What Merchants Pay to Accept Cards
Every card payment costs the merchant a fee, split into three parts:
- The interchange fee is the largest piece. The network sets it and pays it to your issuer. For credit cards, it typically runs from roughly 1.15% to 3.15% of the transaction, depending on card type and merchant category.
- The assessment fee is a smaller fee the network charges to fund its own operations.
- The processor markup is what the payment processor or acquirer keeps for its technology, support, and risk management.
Of the three, only the processor markup is negotiable. Interchange and assessment are set by the network. For a typical credit card purchase, the combined fee usually lands between 1.5% and 3.5%. Debit card transactions cost merchants far less. Under the Federal Reserve’s Regulation II, debit interchange for banks with more than $10 billion in assets is capped at roughly 21 cents plus 0.05% of the transaction.5Board of Governors of the Federal Reserve System. Regulation II (Debit Card Interchange Fees and Routing) Community banks and credit unions below that threshold are exempt.6eCFR. 12 CFR Part 235 – Debit Card Interchange Fees and Routing
These fees are the reason some small merchants set card minimums or add a surcharge for credit.
How the Network Protects You
Tokenization
When you add a card to Apple Pay, Google Pay, or a similar digital wallet, the app doesn’t store your actual card number. The network replaces your account number with a unique token, a substitute number that works for payments but is useless if stolen.7EMVCo. EMV Payment Tokenisation The token is locked to a specific device or merchant, and each transaction generates a one-time cryptographic code, so replaying old data won’t work. When you tap your phone, the token travels through the same authorization, clearing, and settlement process as a physical card. The network translates it back to your real number before sending the request to your issuer, so the merchant never sees or stores your actual card details. EMV chip cards alone reduced counterfeit fraud by 76% to 90% in countries that adopted them early, and tokenization adds another layer on top.8EMVCo. How Do EMV Chip Specifications Tackle Card Fraud
Chargebacks
If you spot an unauthorized charge or never receive what you paid for, the network’s rules give you a route to reverse the transaction. Under the Fair Credit Billing Act, you have 60 days from the date your billing statement is sent to notify your card issuer in writing about a billing error.9Office of the Law Revision Counsel. 15 USC 1666 – Correction of Billing Errors While the issuer investigates, you don’t have to pay the disputed amount, and it can’t be reported as delinquent.
Your issuer then initiates a chargeback through the network, pulling the funds back from the merchant’s acquirer. The merchant can respond with evidence such as a signed receipt or proof of delivery, and a contested case can escalate through a second review and, eventually, network arbitration.10Mastercard. Chargebacks Made Simple Guide The 60-day window is a hard deadline. Miss it and you lose your statutory right to dispute under federal law, leaving you to negotiate directly with the merchant.