Payments feel instant and free to consumers and involve several parties each taking a share.
The parties
Cardholder's bank, merchant's bank, the card network and a processor.
Which each perform a function and each charge for it.
The merchant pays; the consumer generally does not see the cost directly.
Interchange
The largest component, paid to the cardholder's bank.
Which is set by the network and varies by card type and transaction.
Premium rewards cards carry higher interchange, which funds the rewards.
Debit regulation
Debit interchange is capped for larger issuers under specific legislation.
Which is why debit rewards are minimal compared with credit.
Smaller issuers are exempt from the cap.
Bank transfers
Direct account-to-account payment through clearing systems.
Which is cheaper than cards and historically slower.
Instant payment systems have reduced the speed difference substantially.
Settlement timing
Authorisation, clearing and settlement are distinct steps.
Which is why a pending transaction differs from a settled one.
Merchant funds typically arrive days after the transaction.
Chargebacks
Disputes reversing a transaction.
Which impose costs on merchants regardless of outcome.
Rules and timescales are set by the card networks.
Cross-border
Currency conversion, correspondent banking and additional fees.
Which makes international payment substantially more expensive.
Comparing all-in cost including the exchange rate margin is the meaningful comparison.
Consumer protections
Card payments carry dispute rights that bank transfers generally do not.
Which matters when something goes wrong.
Paying by card for anything uncertain is the practical implication.
Surcharging and cash discounts
Passing card costs to customers who use cards.
Which is permitted subject to disclosure and network rules in many places.
Rules differ by state and by card network.
Merchant category codes
Classifications determining interchange rates and reward category eligibility.
Which explains why a purchase sometimes fails to earn expected rewards.
The code is assigned to the merchant rather than to the transaction.
Instant payment systems
Real-time bank transfers between accounts.
Which have been introduced in most major markets.
They shift settlement from days to seconds and carry different dispute rights.
Digital wallets
Tokenised card credentials on devices.
Which improves security by not transmitting the actual card number.
The underlying payment still runs on card rails with card economics.
What consumers should know
Card payments carry dispute rights that transfers generally do not, which matters for anything uncertain.
Fraud liability
Rules allocating loss between cardholder, merchant and issuer.
Which shifted with chip adoption.
Card-not-present transactions carry different liability rules from in-person ones.
Authentication
Additional verification for online transactions.
Which reduces fraud and adds friction.
Requirements differ substantially between jurisdictions.
Payment scams
Fraudsters directing victims to make transfers rather than card payments.
Which removes the dispute rights cards provide.
Reimbursement requirements for authorised push payment fraud have been introduced in some markets.
Small merchant costs
Proportionally higher processing costs for low volumes.
Which is a documented structural feature.
Aggregator services provide access at simplified pricing.
For consumers
Use cards for anything uncertain, since the dispute rights are meaningful and transfers have none.
Who ultimately pays
Merchant fees appear in prices, which means everyone pays them including customers who use cash and earn no rewards.
That distributional point is well documented and is the reason interchange regulation is debated.
The consumer implication
Use cards where dispute rights matter, and understand that transfers are irreversible.
International cards
Foreign transaction fees charged by issuers.
Which some cards do not charge at all.
Choosing to pay in local currency rather than accepting conversion at the terminal is generally better value.
Recurring authorisations
Card-based subscriptions continue even when a card is replaced.
Which updater services enable.
Cancelling with the provider rather than with the bank is the reliable route.
The summary
Several intermediaries, interchange as the largest fee, merchants paying and prices reflecting it.
Cash and its costs
Handling, transport, security and shrinkage.
Which are real merchant costs frequently assumed to be zero.
Studies comparing cash and card acceptance costs reach mixed conclusions depending on transaction size.
Access to payments
Households without bank accounts face higher costs for basic transactions.
Which is documented in financial inclusion research.
Cash acceptance requirements have been legislated in several places for this reason.
The summary
Payment infrastructure is expensive, largely invisible, and paid for in prices by everyone.
A closing note
A payment that feels instant and free involves several institutions and a fee structure embedded in the price of everything.
Knowing that changes how you read arguments about surcharging, rewards and interchange regulation.
Where to read more
Central bank research on payment costs and interchange is published openly and is more informative than any industry material.
A general caution
This describes how the system works and is not personalised financial advice.
Individual circumstances differ substantially, rules change, and anything consequential warrants a qualified professional who knows your situation.
Free and impartial guidance services exist in most countries and are a better first stop than any commercial source.