A guarantee contract is generally a fixed-term contract concluded against the party for who who benefit the contract operates and undertakes to conclude the main or main contract, which includes additional conditions for the same purpose as the main contract.  For example, a contract of guarantee is concluded when one party of the other party pays a certain amount to enter into another contract. A warranty contract may exist between one of the parties and a third party. The Common Law recognizes the contract of guarantee as an exception to the rule of proof parol, which means that admissible evidence may be used for a contract of guarantee in order to exclude the application of the rule of proof parol. In practice, it is rare to find a warranty contract as an exception, as it must be strictly proven; and the burden of proof is facilitated only if the subject matter of the main contract is more unusual.  The main contracts and the ancillary contracts are simultaneously active and, in some cases, the provisions of the latter may prevail over those of the former. For example, companies X and Y conclude a construction contract with X as the client and Y as the contracting authority. Y then concludes a warranty contract with Z, a hardware supplier. If the materials are found to be defective, X Z can sue even though they do not have a contract with each other. It can also be embodied as follows: a guarantee contract is a contract that induces a person to enter into a separate “primary” contract. For example, if X agrees to purchase goods from Y manufactured accordingly by Z, on the basis of Z`s assurance of the high quality of the goods, X and Z may have entered into an ancillary contract consisting of Z`s quality promise, taking into account X`s promise, the main contract with Y has been given.
One theory says that it is possible to accredit as a guarantee contract for a third party, since credits are motivated by the buyer`s necessity and, in application of Jean Domat`s theory, the cause of a credit is that a bank issues a credit in favor of a seller in order to relieve the buyer of his obligation to pay directly to the legal tender seller. There are indeed three different entities that participate in the accrediting transaction: the seller, the buyer and the banker. Therefore, a credit corresponds theoretically to a guarantee contract accepted by the conduct, or, in other words, to an implied contract.  It is briefly referred to as LOC A party to an existing contract may attempt to prove that there is an ancillary contract in the event of a failure of its right to an infringement, because the statement on which it relied was not considered a term of the main contract. . . .