The old name for MasterCard.

Access Control

The process of ensuring that systems are only accessed by those authorized to do so, and only in a manner for which they have been authorized.

Account Number

A unique number assigned by a financial institution to a customer. On a credit card, this number is embossed and encoded on the plastic card.


Banks that make arrangements with businesses to accept credit card sales. When you pay for something in a shop, say the money is sent to the acquirer, who puts it into the shops bank account and sends details of the sale to the credit card issuer. The card issuer records the sale and charges it to your account. The acquirer charges the shop a small fee – usually a few pence. The acquirers in the UK are; Royal Bank of Scotland, Clydesdale Bank, Bank of Scotland, Nat West Streamline, HSBC and Lloyds TSB.

Acquiring Bank

A bank that receives the credit card transactions and then settles with the issuing banks. Bank that signs up / enables the merchant to process transactions.

Additional cardholder

When you have a credit card it is possible to add an additional card to the account for use by someone else. The main cardholder has responsibility for ensuring payments on the additional card are made. Purchases are shown on the credit card statement sent monthly.

Address Verification Service (AVS)

A method of reducing fraud in mail order/telephone order transactions by using cardholder billing address information in the authorisation request.

Affinity Card

Affinity cards are credit cards that are linked to organisations like charities, political parties and sports clubs. They are a good way of raising money as the organisation receives a donation from the card issuer for every card taken out, and a small percentage based on the amount of money you spend on the card each month.

American Express

Also known as AMEX, is one of the main international credit card issuing schemes. It issues it?s own credit cards – unlike Visa and MasterCard and is responsible for it?s own relationships with retailers.

Annual Fee

Some issuers charge for the management of your credit card account. They sometimes provide access to a number of additional benefits as part of the charge. Expressed as % P.A.


American National Standards Institute – The organization that issues standards in the US.


Application Program Interface.

Application Layer

The layer of the ISO Reference Model which provides communication between applications.

Application Security

The provision of security services within user applications running above the Application Layer of the ISO model.

Approval Response

An authorisation response received when a transaction is approved. Authentication – The process of assuring that data has come from its claimed source, or of corroborating the claimed identity of a communicating party.

APR (Annual percentage rate)

This is the amount of interest you will be expected to pay, should you borrow on your credit card. The APR is a figure designed to give consumers some idea of the cost of borrowing on the credit card. Other factors such as the date from which the interest is charged and the number of days you have to pay the interest also affect the cost of borrowing.


American Standard Code for Information Interchange – The standard system for representing letters and symbols. Each letter or symbol is assigned a unique number between 0 and 127.


Automated Teller Machines, cash points, allow you to access cash with a credit card or other card associated with your bank account. You need to enter your personal identification number (PIN) into the machine to access cash.


Every retailer has a purchase limit above which they must seek authorisation from the card issuer before they can complete the sale. This can be done by telephone or electronically at the cash till. Authorisation is used to control credit card fraud. The cardholder?s available credit limit is reduced by the authorized amount.

Authorisation Amount

Currency amount approved.