What is a Card Scheme?

What Is a Card Scheme?

A card scheme -- also called a card network or card brand -- is the organisation that operates the payment network connecting cardholders, card-issuing banks, merchants, and acquiring banks. The card scheme sets the rules, standards, and infrastructure that make card payments possible across millions of merchants worldwide.

The major global card schemes are Visa, Mastercard, American Express, Discover, JCB, and UnionPay. When you see one of these logos on a payment card or a merchant's window, it indicates which network the card runs on and where it can be accepted.

How Card Schemes Work

A card scheme does not issue cards directly to consumers or process payments for merchants (with some exceptions like American Express). Instead, it operates the network that sits in the middle, connecting:

• Issuing banks -- The banks that give cards to consumers (e.g., Barclays issuing a Visa debit card)
• Acquiring banks -- The banks that enable merchants to accept card payments
• Cardholders -- The consumers who use the cards to make purchases
• Merchants -- The businesses that accept card payments

When a customer makes a purchase, the transaction flows from the merchant through the acquiring bank, across the card scheme's network, to the issuing bank -- and the response flows back. This entire round trip typically takes just a few seconds.

The Four-Party Model vs the Three-Party Model

Four-party model (Visa, Mastercard)

In the four-party model, the card scheme operates purely as a network. It does not issue cards or manage merchant accounts. Four separate parties are involved in each transaction: the cardholder, the issuing bank, the acquiring bank, and the merchant. Visa and Mastercard are the primary examples of this model.

This model allows for massive scale because thousands of different banks can issue cards and acquire merchants on the network.

Three-party model (American Express, Discover)

In the three-party model, the card scheme acts as both the network and the card issuer (and sometimes the acquirer). American Express is the best-known example -- it issues cards directly to consumers and has direct relationships with merchants. Discover historically operated similarly, though its acquisition by Capital One is evolving this model.

The three-party model gives the scheme more control over the customer experience but limits scale because the scheme must manage all issuing and acquiring relationships itself.

What Card Schemes Actually Do

Beyond operating the payment network, card schemes perform several critical functions:

• Set interchange rates -- The fees that flow between issuing and acquiring banks for each transaction
• Establish operating rules -- The regulations that all participating banks and merchants must follow
• Manage disputes -- Card schemes run the chargeback and dispute resolution processes
• Drive innovation -- Developing new payment technologies like contactless payments, tokenization, and real-time fraud detection
• Enforce security standards -- Card schemes are founding members of the PCI Security Standards Council and require participants to maintain PCI DSS compliance
• Manage brand and acceptance -- Building global acceptance networks so cardholders can use their cards virtually anywhere

Card Schemes and Interchange Fees

One of the most commercially significant roles of card schemes is setting interchange fees -- the fees paid by the acquiring bank to the issuing bank on each transaction. These fees ultimately determine much of the cost merchants pay to accept card payments.

In the UK and EU, interchange fees for consumer cards are capped by regulation: 0.2% for debit cards and 0.3% for credit cards. These caps were introduced by the EU's Interchange Fee Regulation and have been retained in UK law post-Brexit. However, additional scheme fees charged by Visa and Mastercard are not capped and have been rising -- a source of ongoing tension with merchants.

Card Schemes in Telephone Payments

For telephone payments, the card scheme determines several practical aspects of the transaction:

• Which card types your payment gateway can process
• The interchange rates you will pay (which differ for card-not-present transactions)
• The chargeback rights and timelines that apply
• The security requirements, including PCI DSS compliance

Card-not-present transactions -- including telephone payments -- typically carry higher interchange rates than card-present transactions because they are considered higher risk. This is one reason why strong security measures like DTMF masking are valuable: they reduce fraud risk and can help justify more favourable processing terms.