Credit Card Companies Explained: Visa, Mastercard, Amex, & Discover

We usually think about rewards, APRs, or perks when choosing a credit card. But how often do you consider the network behind it?

There’s more to networks like Visa, Mastercard, American Express, and Discover than just their names. Each one has its own rules, fees, and ways of processing transactions — and those differences can impact your business’s costs.

In this guide, we’ll break down what card networks actually do, how their fee structures work, and how they affect your business’s credit card selections and processing choices.

What Is A Credit Card Company?

A credit card company, also called a credit card network, can refer to a card brand and/or a card issuer.

The most common brands are Visa, Mastercard, American Express, and Discover.

Credit Card Brand VS Credit Card Issuer

Are card brands the same as card issuers? Sometimes (but usually not).

A credit card issuer is typically a bank that provides you with a credit card, essentially giving you a revolving line of credit to pay for your purchases. They handle the lending, billing, and interest.

A card brand (like Visa or Mastercard) doesn’t lend money. Instead, it sets rules and fees (such as interchange rates) that banks, processors, and merchants must follow. If you break the rules, the brand can restrict your ability to process those cards.

American Express and Discover work differently. Each operates both as a card brand and issuing bank, using its own network to issue cards and process transactions.

How Do Credit Card Companies Work?

Think of credit card networks like a franchise system:

• Visa and Mastercard: Franchisors
• Issuing banks: Franchisees
• Cardholders: Customers

American Express and Discover are like franchisor-owned stores: they handle both the network and the issuing bank functions directly.

Franchisors (card networks) set rules for the franchisees (issuing banks) and enforce them, just like Visa and Mastercard set guidelines for banks.

They also handle marketing, which is why you recognize the brand more than the issuing bank. You know you have a Mastercard, but the bank that issued it often seems invisible.

This franchise analogy isn’t perfect because it doesn’t capture everything networks do. But it gives a useful framework for understanding the system. This matters because the network’s rules and fees directly affect how you accept payments and how much it costs.

Are Credit Card Networks The Same As Debit Networks?

Debit transactions can run on two types of networks:

• PIN debit: Routed through a separate network with immediate fund transfer. Usually carries lower interchange fees than credit-based debit.
• Credit-based debit: Routed through the credit card network, but funds are pulled from the account immediately.

Some card networks also own debit networks (for example, Discover runs the PULSE network). So under certain circumstances, a credit card network can also process debit transactions.

To simplify things further, here’s a quick comparison of how credit and debit transactions move through networks:

Why Credit Card Companies Matter For Payment Processing

Not all credit card companies handle processing fees the same way. Understanding how transactions flow helps explain the differences between Visa, Mastercard, American Express, and Discover.

Key players in a card transaction:

• Cardholder: The consumer making the purchase
• Issuing bank: The bank that gave the card to the consumer
• Acquiring bank: The bank that processes payments for the merchant
• Card network/association: Visa, Mastercard, Amex, or Discover
• Processor: The company that handles the technical side of the payment
• Merchant: The business accepting the payment

With that in mind, here’s how a payment works:

1. The card info is encrypted and sent from the merchant to the processor.
2. The processor identifies the acquiring bank and sends the transaction along.
3. The acquiring bank forwards it to the appropriate card network (Visa, Mastercard, Amex, Discover).
4. The card network matches the transaction to the correct issuing bank and runs fraud or verification checks. (Amex and Discover skip this as they are their own issuing banks.)
5. The issuing bank verifies credit availability and approves or declines the purchase.
6. Authorization travels back through the network to the merchant.
7. If approved, funds move from the issuing bank to the acquiring bank, then to the processor, and finally to the merchant.
8. The issuing bank bills the cardholder for repayment later.

Bottom line: Card networks play a crucial role in moving transactions along — and they charge fees for it.

The Role Of Credit Card Companies

Credit card brands play a huge role in payment processing beyond just slapping a logo on a card. Here’s what they actually do.

How Credit Card Networks Affect Your Small Business

Even if you don’t deal directly with Visa, Mastercard, American Express, or Discover, their decisions have a real impact on your business.

These networks influence:

• Processing fees: What you pay to accept card payments.
• Rules and compliance: What standards and practices you must follow.
• Customer reach: How many cardholders can shop with you.
• Card structure: How cards are issued and used by consumers.

Knowing these differences can help you choose which cards to accept and manage costs effectively.

Accepting Different Card Brands Through Your Merchant Account

Years ago, merchants often accepted only one or two card brands. Some restaurants took only American Express for lower interchange rates, and Discover struggled with adoption.

Today, most processors allow merchants to accept all four major brands. However, some organizations (like certain government agencies) still accept only Visa or Mastercard for ease of convenience fees. Before signing a processing contract, confirm with your processor which cards you can accept.

To choose the right solution, check out the best payment processors for your business. Or, if you are in the market for getting a credit card for business use, check out our list of the best business credit cards to find the right card for any situation.