The guarantee contract is a convention that refers to personal guarantee by virtue of which a third party, unrelated to the main guaranteed business, undertakes to respond, subsidiarily or jointly, for compliance with the creditor, instead of the debtor, who is the principal obligor, in the event that the latter does not comply.[1]​

The guarantee contract is basically free and consensual, since it is perfected "Perfection (Law)") by the simple manifestation of the guarantor's will accepted by the creditor, whether the debtor wants it and knows it, or even if he ignores it.

Contenido

El contrato de fianza presenta los siguientes caracteres:.

Accessory

The guarantee presupposes the existence of a main obligation to which it agrees, and by virtue of this character it is contaminated by the nullity of the main contract, its extinction, or its transferability, by the principle that establishes that the accessory follows the fate of the main one.[2]​.

Consensual

It is concluded to produce its own effects as soon as the parties have reciprocally expressed their consent.[2]​.

Commutative

Because the parties know the advantages and disadvantages that are sought from the moment the bond is established. Although there is uncertainty as to whether the debtor complies with the obligation or not, it does not mean that it is subject to randomness, because the advantages and disadvantages of the contract are not affected, it is only subject to one condition.[2]​.

Unilateral

The surety is normally a unilateral contract since it only creates obligations for the guarantor.[2]​.

Gratuitous

The fact that the guarantor is recognized with the power to stipulate with the debtor a remuneration for the favor provided does not mean that the surety is no longer free, since the debtor is not a party to the contract.[2]​.

Subsidiary

This is a characteristic of the obligation and not of the contract, by virtue of which only the guarantor will be required to fulfill the obligation in the event of non-compliance by the main debtor.[2]​.

The bond is extinguished: