Usury is the term applied to describe the action of collecting extra money for the time it takes a customer to pay a sum that was loaned to him, which is known as “interest”; in other words, it is the collection of the credit or the profit obtained by having given money in a certain time. According to this, the word has been applied to mention all those individuals who charge exorbitant interest, that is, those who have an immense profit when applying this work technique, then the clients describe it as "usurious" people.

However, usury is not a purely economic term (there is no profit figure that is indicated as usury), it is totally the opposite, the definition of usury is a word of social origin where each individual according to his empirical economic criteria defines which is a sensible sum and which becomes priceless. Many societies disagreed with the application of the interest payment, where each sum (however minimal it was) was crossed out as usury, so much was the social discontent that it was formalized as an illegal act and the lenders were individuals who used to work in secret of the law for a long time.

In fact, in the Spanish nation a law was created in favor of the “repression of usury” (July 23, 1908), popularly known within society as “Ley Azcárate”; This rule imposes as totally null all those contracts that were signed between two or more individuals, where the requirement of an extremely important payment bordering on the preposterous is exposed, which means the interest of a monetary loan that has been granted.

Other cases where the collection of interest is canceled or illegal would be such as:

1. An amount totally disproportionate to the loan that has been made.
2. The loan is under a contract whose origin is insidious and has signatures that are considered illegal or illegitimate (example: signed by a person who does not have psychiatric health, or adults with very advanced age and ends).
3. When the demand for payment to return is totally far from the initial negotiated sum