In our days many reasons exist to make use of the credit. The possibility of carrying a plastic card instead of a pile of tickets is very advisable without stopping considering the reason but obvious, which is not other that the fact that it is more and more difficult to live in the society of today without having antecedents registered in the networks that control the use of the credit. Without a doubt the credit cards are necessary for, for example: to reserve hotels, to rent automotive vehicles, to carry out purchases by catalogue or telephone. In some places it is necessary to own a credit card until being able to rent videos, without stopping mentioning the indispensable thing that turn out to count on a good credit if it is tried to obtain a loan in cash, with a reasonable interest, to the acquisition of an automobile or a house. The credit cards also offer a sense of endorsement or security because it is attributed to them that they have the power to solve situations of emergencia, like unexpected diseases, accidents or expensive repairs of urgent accomplishment. Lamentably along with these advantages some disadvantages coexist then because when offering a security sense induces the individual not to resort to the personal saving for the cover of emergencia situations. The good use of the credit demands of whom it owns the consideration of some essential points: The purchases on credit can be but considerably expensive due to the payment from interests and additional costs when the balances are not cancelled in time and forms, without unknown that the holders of credit cards run the risk of being exposed to swindles and frauds they misled if them or the number of its account was copied to them. Counting on a certain one to be able of purchase can take to the temptation to fall in the overdraft being created a situation it jeopardize in the future, whenever we entered unevenness in the relation entrance-debits, the costs of the landslide of the covered victories could not jeopardize the familiar economy seriously, with the consequent conflicts that situations of this type carry generally.