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Not exactly a banker? Check out our glossary of financial terms.

3D Secure

Three Domain Secure (3D Secure) is a regulatory requirement specified by EMVCo to ensure safe and secure online card transactions.

3D stands for the three domains that are the browser, the issuing bank, and the card network. It is a mandatory requirement that from 1.01.2021 all EEA merchants must process all card transactions as 3D Secure. Merchants in other EU countries and non-EU cards can be out of scope for 3D Secure payment processing.

Different card brands call it by their unique names:

  • Verified by Visa
  • Mastercard SecureCode
  • J/Secure
  • American Express SafeKey
  • Discover ProtectBuy
  • UnionPay 3D Secure 2.0

To learn more about 3D Secure and SCA, go to 3D Secure


The institution where the merchant has the settlement account for credit card transactions. This is the account where the money is finally credited after a card transaction. The acquirer has a direct contract with the merchant of record.

Acquirer Reference Number (ARN)

This is a unique number that is assigned for a transaction when the transaction is processed by the card scheme. This number is required when there is a refund request by the customer’s bank, this number is used to uniquely identify the acquiring bank and the transaction.


The process of verifying the transaction and reserve the amount for capturing it later. The acquirer sends the authorization request to the issuer and the issuer will reserve the specified amount on the respective account. The merchant should either capture the authorization or reverse the specified amount within 7 days.

You can also cancel an authorization (reversal) before you charge the payment. If you cancel an authorization after payment, it is called refund.

Bank Identification Code (BIC)

Identifies a specific bank for an international transaction. BICs are issued by SWIFT as an ISO registration authority. It consists of 8 or 11 alphanumeric characters. The first 4 characters are the business party prefix, the next 2 alphabets are the country code, and the last 2 alphanumeric are business party suffix.

Bank Identification Number (BIN)

The first 6 to 8 digits that are printed on the credit or debit card. It is used to identify the the issuing bank, origin of the card, and the type of card.

Basket API

This API processes the basket information for a customer payment. Some details include basket item descriptions, unit prices, discount information and risk scoring related data. This information is used for

  • rendering the shopping basket on a Payment Page or Pay-by-link page
  • enabling risk scoring on the Unzer side
  • displaying a summary of the shopping basket on the checkout page of a certain PSP (for example, PayPal)

Basket Value

It is the final total amount (incl. VAT) in processing currency deducted for all discounts.

You can also give the flexibility to add vouchers and discount codes. Discounts can be applied as a percentage or a specific amount to each basket item separately. For more on baskets, see manage baskets.


The person or entity that purchases goods and services from the merchant. Also referred to as consumer or customer.


The process of moving funds from the consumer’s account to the merchant. This is also known as capturing a charge.

Card schemes

The network providers that provide the necessary infrastructure for processing payments. The issuing bank and acquiring bank must be members of the same network for payment transaction. Some examples of well-known network providers and card schemes are Visa, Mastercard, American Express (AMEX), Japan Credit Bureau (JCB), Diners/Discover, and China Union Pay.

Card number

The number that is printed on the debit or credit card. This number is used to identify the customer during the transaction and used for payment by the issuing bank.

Card Verification Code (CVC)

Card verification code is the 3 or 4-digit number that is printed on the credit or debit card and used for card-not-present transactions. This number uniquely identifies the card and is used for authentication of an online transaction.

Also known as:

  • CSC (card security code)
  • CVD (card verification data)
  • CVN (card verification number)
  • CVV (card verification value)
  • CVVC (card verification value code)
  • V-code or V code (verification code)
  • SPC (signature panel code)

Charge (Capture)

The process of debiting money from the customer’s account as a payment for the goods and services that they have purchased from the merchant. This is also known as capture.

  • For 2-step procedure, authorize and charge, you can charge only after authorization is successful.
  • For 1-step procedure, that is direct charge, authorize and capture are performed immediately.


A transaction where the customer’s bank (Issuer) requests to fully or partially reverse a transaction. A chargeback occurs when a card owner refuses to pay. In this case, the issuer raises an objection with the acquirer and demands the transaction amount back from the merchant. The merchant must now justify why they do not want to return the money.

Chargeback fee

A fee charged by the issuer when an already processed payment is returned for credit. One reason for such a chargeback is undelivered or incompletely delivered goods from the merchant. See also Chargeback.

Contactless payments

Contact-less payments are an advanced form of paying for goods and services where you do not need to physically swipe or present your card. You can pay by simply using your phone which will communicate via NFC with the POS device. Examples are Apple Pay and Google Pay.

Direct debit

A financial transaction in which one entity (the payee) withdraws funds directly from another entity’s (the payer’s) bank account. Also known as a direct withdrawal.

Direct Debit Return

A message transfer from merchant to the customer when either the bank account of the customer is closed or has insufficient balance. It is also possible that the payer now has to pay a reprocessing fee or a penalty.


The reduced percent or fraction amount for one or more items that the customer adds to their basket. Discounts can differ per basket item. For example, to process discount information, such as:

  • 10% discount on every basket item, except pet food
  • 30% discount on basket item 1, 15% discount on basket item 2

Electronic Commerce Indicator (ECI)

A value that is returned by the 3DS directory server and the card network when authenticating a cardholder and the status of the issuing bank. This is mandatory for 3DS payment transactions.

Electronic Funds Transfer

Paperless payment transaction, where the payment amount is electronically transferred from the buyer account to the supplier account. This can be executed via accounts from the same bank or between various banks. Monthly installments or salary payments are some examples.


EMVCo defines the global guidelines for accepting secure payments. It is collectively owned by American Express, Discover, JCB, Mastercard, UnionPay and Visa. For more information about EMVCo, go to Overview - EMVCo.


Fraud is a suspicious activity where an unauthorized person or entity tries to deceive the customer or the merchant. Fraud prevention measures must be implemented to avoid this and also save the various entities from financial, personal, or reputation loss.

Fraud prevention

The glossary entry fraud prevention consolidates credit and plausibility checks. However, these also include additional checks, such as CVS or the validity date on credit cards or other approaches, such as the number and location of transactions during a time window. However, other fraud prevention checks may include queries to credit rating agencies, such as SCHUFA and Blacklists.


When we talk about fulfillment in the payment flow we either mean the actual shipment in case of ordering physical goods or the providing and enabling of a service/content in case of a digital purchase.

International Bank Account Number (IBAN)

IBAN is a 16-digit account number for the specific customer bank account. The IBAN is registered by SWIFT as designated by ISO. The ISO 13616 according to the standard for numbering bank accounts. (external link: International Bank Account Number)


Installment is a payment type where the consumer does not pay for the goods or services in full, but in parts or Installments. (The Unzer Installment payment method is available for such transactions.)

Installment plan

An arrangement how much the customer has to pay, in what frequency, and the duration of the payment. Also known as hire purchase.


A request for payment, issued before the payment. An invoice is raised when the merchant sends the goods and requests for payment from the customer. It is also known as tab or bill.

Invoice secured/Buy now, Pay later

When using our secured Unzer white label solution, we are not visible as a third-party provider to your shoppers. The UI components and all communication means are visually matched to the appearance of your brand.

Issuing bank or Issuer

The bank or financial institution that issues the card to the customer. They are responsible for billing and collection of funds for the transactions that are performed using this card. They also validate the customer bank account or credit card details.

Japan Credit Bureau (JCB)

JCB Co. Ltd. formerly known as Japan Credit Bureau, is a Japanese card issuer and network provider. It is also a member of the EMVCo who define the policies for card payments.


The legal entity that sells goods and services to the customers and is obligated to provide the sold goods. A merchant can include a small local bakery to a big online shopping website.

Mobile wallet

An application on the mobile device of the customer that they can use for making payments. It is linked to a credit or debit card that is used for transactions. For example, Google Pay are Apple Pay.

Near Field Communication Technology

NFC technology describes wireless transmission of data over short distances (near field), for example, by smartphone or tablet. It supports transmission of data using radio technology over short distances of only a few centimeters for purposes of cashless payments. It is frequently used for mobile cashless payments of small amounts. A condition for paying with NFC is an NFC-enabled acceptance location at the POS and an NFC-enabled credit card or a smartphone or tablet with an NFC-enabled SIM card or NFC Sticker.


A multichannel approach to provide the customer with a seamless and integrated shopping experience. This means that the customer can easily transition between phone to email to POS without hampering the shopping experience.

Primary Account Number (PAN)

A unique 14-19 digit number used to identify a primary account. It is also called as payment card number because it is available on the credit or debit card.

Payment Service Provider (PSP)

A company or organization that processes payment transactions for merchants. Unzer is a PSP that processes transactions for merchants who want to accept various payment methods in their shops.

Personal Identification Number (PIN)

A four-digit number for the card, used to identify the card owner. The customer can use the PIN (only known to them) to withdraw the money at an ATM or process a payment at the POS machine.


A PCI Self-Assessment Questionnaire is a document that the merchant fills to show that they are compliant on a certain PCI level. It contains a list of standards and security measures that their business must follow to process credit card transactions.


The Point-of-Sale (POS) is the terminal device at which the customer pays for their goods or services. The terminal device accepts credit cards, debit cards, and wallets. POS terminals are used world-wide and conveniently process cashless money transfers.


A proof of payment, issued after the payment and shows the details of the transaction.


When the customer returns the goods for some reason, the merchant has to refund the money to them. It has a new transaction ID, and capture and authorization are not possible for this transaction.


The process of canceling an authorization for a transaction that has not been captured. This means that the authorization is done, but the money is not yet transferred from the customer to the merchant.

SCHUFA Protective Association for General Credit Security

SCHUFA (Protective Association for General Credit Security—Schutzgemeinschaft für allgemeine Kreditsicherung) is a private enterprise established by the banking industry to grant credit. It provides a source of information for businesses to protect them against receivables default. The data is either collected directly by SCHUFA or reported by various contractual partners. In addition to the master data about a person or a company, SCHUFA collects information about applying for and terminating credit services and about payment patterns.

The data collection for various scoring algorithms incorporates credit infractions and requests for credit, details from public directories, such as arrest warrants or insolvency proceedings, and other characteristics. A probability value for a potential non-payment is determined based on this by employing a mathematical/statistical algorithm.

Settlement Currency

The currency used to for settlement of the payment for goods and services. This is the currency in which the merchant is paid.


Single Euro Payments Area (SEPA) makes it easier for cross-border cashless euro payments as easy and convenient as domestic euro payments. Some of the advantages are:

  • easier cross-border transaction in the same currency
  • receive funds in other countries in the same currency for payments in the SEPA member country
  • uniform schemes for transactions allowing for more transparent, fast, and easy payments.

SEPA Mandate

A form filled by the customer that allows the merchant to deduct funds from the customer.


The Society for Worldwide Interbank Financial Telecommunication is an international organization that enables and provides regulations for all financial transactions in a secure, safe, and standard format.


The SWIFT code (Society for Worldwide Interbank Financial Telecommunication), also called BIC, consists of 11 characters used to uniquely identify a bank. The SWIFT code consists of: 4-digit bank code, 2-digit country code, 2-digit encoding of the location, and a 3-digit code for the branch.

Transaction Authentication Number (TAN)

A one-time password (OTP) assigned by the issuer. It is used as a two-factor authentication for online payments in addition to the PIN as confirmation.

Value-added Tax (VAT)

The tax that the end customer pays for the goods and services they purchase. This is the total tax incurred from manufacturing to retail sale that is paid by all the entities that are involved in the supply chain.


It is the incentive given to the customers as a reward for previous purchases, subscriptions, promotions, and so on. The customer can use the voucher when making a payment.

For example, the customer gets €5.00 voucher for registering to the newsletter.


A wallet or e-wallet is an online account or application that the customer can use to make online or mobile payments. It can also be installed as an app on the phone and be used for making payment at a terminal. A wallet is usually linked to a bank account that is used for transferring money to the wallet. Some of the examples of wallet include Apple Pay, PayPal, and Amazon Pay.