Interchange, network fees, and the merchant discount rate

The merchant discount rate is the merchant’s percentage price for card acceptance under its pricing arrangement. Interchange is a component paid to the card issuer in a four-party system; it is not the whole merchant acceptance charge or the fee retained by the card network.

A card payment supports several recipients

In a four-party arrangement, the cardholder uses an issuer’s card to buy from a merchant served by an acquirer. The network connects issuing and acquiring participants under its rules.

Interchange transfers value from the acquiring side to the issuer. It contributes to the economics of issuing, including account service, authorization, fraud controls, and funding where the product extends credit.

Network fees pay the scheme for network services. Acquirer and processor charges compensate merchant-side providers for processing, service, infrastructure, and the risks they bear. Their revenue is not all profit: it must cover their own costs and losses.

The merchant’s total charge is not interchange

Take a $100 purchase with $1.60 of interchange, $0.15 of network charges, and $0.75 of acquiring and processing charges. The combined transaction cost is $2.50, or 2.5% of the purchase amount. The issuer receives the $1.60 interchange component, not the whole $2.50.

A merchant receiving $97.50 from that sale cannot infer the recipients of the missing $2.50 from the payout alone. The pricing agreement and statement supply that decomposition. Other deductions, such as reserves, refunds, or adjustments, require separate treatment.

Pricing format changes what the merchant can observe

Interchange-plus pricing exposes interchange separately from a provider’s markup, although other charges still need examination. A blended percentage combines components into a merchant-facing rate. A percentage-plus-fixed-fee price adds a charge for each transaction.

Ticket size changes the effective percentage. Take a $0.10 fixed fee: it equals 2% of a $5 purchase and 0.1% of a $100 purchase. Comparing headline percentages without transaction sizes can therefore reverse the apparent ranking of two offers.

Card mix, channel, geography, and the services purchased also change acceptance cost. A negotiated percentage is not a universal price for every card or merchant.

Three-party arrangements allocate revenue differently

In an integrated three-party arrangement, one operator can hold both the cardholder and merchant relationships. It receives merchant discount revenue without the same external interchange transfer between separate issuing and acquiring institutions.

Issuing and acquiring costs still exist inside the integrated business. Hybrid arrangements involving outside issuers or acquirers require their own allocation. The test is which entities hold the relationships and receive each payment.