Payments vocabulary in one hour. 6 chapters and a final quiz.

Chapter 1. Setting the scene: a transaction and its four parties.

“The acquirer rejected the capture, so we'll have to represent the chargeback.” To a newcomer, that sentence is opaque: payments have a jargon of their own, and a vocabulary mistake can be expensive. Confusing authorization with debit throws off a reconciliation; confusing acquirer with merchant makes a contract unreadable. The whole vocabulary is built around the card and its four-party model.

Two things travel between these four parties: messages (authorization requests, clearing) and money (settlement). A fifth player sets the rules: the scheme, or card network, such as Visa, Mastercard, or CB. In the real world, a swarm of technical providers sits in between. The next chapter covers them.

Chapter 2. The players: who does what in the chain.

Around the four parties orbits a whole ecosystem of providers, known generically as PSPs (payment service providers). In the EU regulatory sense, the term covers any institution authorized to provide payment services: banks, payment institutions, and e-money institutions. In everyday e-commerce usage, “PSP” means the provider that collects payments for the merchant (Stripe, Adyen, Worldline, etc.).

Since PSD2 (2018), two new regulated businesses have rounded out the picture. A payment initiation service provider (PISP) triggers a credit transfer from the customer's account, with their consent. An account information service provider (AISP) accesses accounts to display or analyze them. Together, these two businesses make up open banking.

One last player term: BNPL (buy now, pay later), the installment or deferred payment offered at checkout. The revised Consumer Credit Directive (CCD2, to be transposed by the end of 2025 and applicable from the end of 2026) is gradually bringing it into the scope of regulated credit.

Chapter 3. The flows: authorization, capture, clearing, settlement.

Flow vocabulary causes the most misunderstandings, so let's start with the timeline. A card transaction goes through four stages, each with its own precise term: authorization, capture, clearing, and settlement.

In PSP dashboards, these stages show up as statuses: authorized, captured, settled, refunded. A typical webhook looks like this:

{
  "event": "payment.captured",
  "transactionId": "tr_20260711_8f2c",
  "amount": { "value": 100.00, "currency": "EUR" },
  "status": "captured",
  "history": [
    { "status": "authorized", "at": "2026-07-11T09:14:02Z" },
    { "status": "captured",   "at": "2026-07-11T18:00:11Z" }
  ],
  "settlement": { "expected": "2026-07-13", "fees": { "mdr": 1.20 } }
}

Outside cards, the vocabulary changes. A credit transfer (SCT) is pushed by the payer, while a direct debit (SDD) is pulled by the creditor under a mandate. An instant credit transfer (SCT Inst) settles in under 10 seconds, and these instruments, which move money from one account to another, are called A2A (account-to-account).

Chapter 4. Security and fraud: the vocabulary that protects you.

Security vocabulary revolves around one question: how do you prove that the payer really is the cardholder, and keep card data from being stolen? The first pillar is SCA (strong customer authentication), mandated by PSD2. It requires two factors from three categories: something I know (a code, a password), something I have (a phone, a card), and something I am (biometrics).

Chapter 5. After the payment: back office, disputes, and chargebacks.

Once the customer has left, the back office goes to work. It has to check that every sale was actually paid, process refunds, and fight chargebacks. The first term is reconciliation. It matches three sources that don't speak the same language: the site's orders, the PSP's transactions, and the transfers received at the bank.

The chargeback follows a procedure codified in detail by the schemes. The cardholder disputes the transaction with their issuer, which pulls the funds back from the acquirer with a standardized reason code (fraud, item not received, duplicate transaction, etc.). The merchant can fight back by providing evidence, a process called representment. If the disagreement persists, the scheme decides in arbitration, and every transaction can be traced end to end by its ARN (acquirer reference number).

Chapter 6. Traps, false friends, and insider acronyms.

That leaves the vocabulary mix-ups that give a beginner away. The table below collects them one by one: reread it before every meeting.

The final quiz and the flashcards will lock it all in. Payments vocabulary is learned like a living language: through repetition.