How payments work

A card payment passes through five parties, in two steps: the payer's bank first authorizes it, and the money moves only when you capture it.

Who takes part

The payer is the cardholder, who pays with a card, either typed in or kept in a wallet such as Apple Pay or MobilePay.
The issuer is the payer's bank, which issued the card. It decides whether to approve each payment, and holds the money until you capture it.
The card scheme is Visa, Mastercard, Dankort, or the like. A scheme carries messages between issuers and acquirers, and sets the rules for both, such as how long an authorization lasts.
The acquirer is your bank for card payments, such as Clearhaus or Nets, with which you have an acquiring agreement. It sends your payments to the schemes, pays the money out to you, and passes chargebacks on to you.
gjold is the payment gateway. We host the payment window where the payer enters their card, run 3-D Secure, and send the payment to your acquirer. We never hold your money: your acquirer pays it out under your agreement with them.

From authorization to payout

Authorization. The payer pays in our payment window. We ask the issuer, through your acquirer and the scheme, to approve the amount. The issuer checks the card and the payer's balance or credit, perhaps asks the payer to confirm with 3-D Secure, and approves. It then holds the amount on the payer's account. No money has moved. See Authorizations.
Capture. When you deliver, you capture the amount, or a part of it. The acquirer sends the capture to the scheme for clearing, and the issuer moves the money from the payer's account. See Captures and refunds.
Settlement. The acquirer pays out what you captured, less its fees, on the schedule your agreement sets, often a few days later.
Refund. If the payer returns the goods, you refund all or part of what you captured, and the money goes back to the same card.

Before a capture, you can instead void the authorization, which releases the held amount on the payer's account. And for months after it, the payer can dispute the payment through their bank, which is a chargeback.

The states of a payment

The API docs call an authorized payment a transaction, and show its state as amounts rather than one status, since a transaction can be partly captured and partly refunded at once. In the transaction object:

Amount	What it is
`authorized`	What the issuer approved: the whole amount of the payment.
`captured`	What you have captured so far. While it is less than `authorized`, you can capture more.
`refunded`	What you have refunded so far, at most `captured`.
`voided`	`0`, or the whole amount once the authorization is voided.
`left`	What can still be captured.

A payment that the issuer declines never becomes a transaction: the payer sees the decline in the payment window, and can try again with another card.

Payments without the payer

A payment that the payer makes, in the payment window, is customer-initiated. Once the payer has saved their card as a subscriber, you can also charge it without them, which is merchant-initiated. The schemes treat the two differently, from 3-D Secure to how often a declined charge may be tried again: see Stored credentials.