A credit-debt relationship is defined as ‘that which is owed by one entity to another.' An entity may be an individual, company, government or any other type of institution or organization. Credit and debt represent flip sides of the same coin. Credit is that which is provided, debt that which is owed (Finlay 2005 p.3)

Credit need not necessarily be based on formal monetary systems. The credit concept can be applied in barter economies based on the direct exchange of goods and services, and some would go so far as to suggest that the true nature of money is best described as a representation of the credit-debt relationships that exist in society (Ingham 2004 p.12-19).

Consumer credit

Consumer credit represents one area in which credit-debt relationships exist and can be defined as ‘money, goods or services provided to an individual in lieu of payment.' Common forms of consumer credit include credit cards, store cards, motor (auto) finance, personal loans (Installment loans), retail loans (retail installment loans) and mortgages. This is a broad definition of consumer credit and corresponds with the Bank of England's definition of "Lending to individuals". Given the size and nature of the mortgage market, many observers classify mortgage lending as a separate category of personal borrowing, and consequently residential mortgages are excluded from some definitions of consumer credit - such as the one adopted by the Federal Reserve in the US.

The cost of credit is the additional amount, over and above the amount borrowed, that the borrower has to pay. It includes interest, arrangement fees and any other charges. Some costs are mandatory, required by the lender as an integral part of the credit agreement. Other costs, such as those for credit insurance, may be optional. The borrower chooses whether or not they are included as part of the agreement.

Interest and other charges are presented in a variety of different ways, but under many legislative regimes lenders are required to quote all mandatory charges in the form of an Annual Percentage Rate of Charge (APR). The goal of the APR calculation is to promote ‘truth in lending,' to give potential borrowers a clear measure of the true cost of borrowing and to allow a comparison to be made between competing products. The APR is derived from the pattern of advances and repayments made during the agreement. Optional charges are not included in the APR calculation. So if there is a tick box on an application form asking if the consumer would like to take out payment insurance, then insurance costs will not be included in the APR calculation (Finlay 2005 p.34).

Institutional credit

The term credit is used similarly in commercial trade, known as "trade credit", to refer to the approval for delayed payments for purchased goods. Sometimes, credit is not granted to a person who has financial instability or difficulty. Companies frequently offer credit to their customers as part of the terms of a purchase agreement. Organizations that offer credit to their customers frequently employ a credit manager.