AGREEMENT 1326. Formation of contract. A contract is formed at the moment when he who made the offer has knowledge of the acceptance of the other party. The acceptance must reach the offeror within the time set by him or within that ordinarily necessary according to the nature of the transaction or usage. The offeror can treat late acceptance as effective, provided that he immediately so informs the other party. When the offeror requires a specific form of acceptance, the acceptance is ineffective if given in a different form. An acceptance that does not conform to the offer is equivalent to a new offer. 1333. Contract binding on offeror only. An offer for the purpose of forming a contract that creates obligations only for the offeror is irrevocable as soon as it comes to the knowledge of the party to whom it is directed. The offeree can reject the offer within the time required by the nature of the transaction or by usage. In the absence of such rejection the contract is concluded. 1336. Offer to public. An offer to public, when it contains the essential terms of the contract toward whose formation it is directed, is effective as an offer, unless it appears otherwise from the circumstances or usage. Revocation of the offer, if made in the same form as the offer or in the equivalent form, is effective even as to one who has no notice of it. 1337. Negotiations and pre-contractual liability. The parties, in the conduct of negotiations and the formation of the contract, shall conduct themselves according to good faith. 1338. Knowledge of reasons for invalidity. A party who knows or should know the existence of a reason for invalidity of the contract and does not give notice to the other party is bound to compensate for the damage suffered by the latter in relying, without fault, on the validity of the contract. 1341. Standard conditions of contract. Standard conditions prepared by one of the parties are effective as to the other, if at the time of formation of the contract the latter knew or should have known of them by using ordinary diligence. In any case conditions are ineffective, unless specifically approved in writing, which establish, in favour of him who prepared them in advance, limitations on liability, the power of withdrawing from the contract or of suspending its performance, or which impose time limits involving forfeitures on the other party, limitations on the power to raise defenses, restriction on the contractual freedom in relations with third parties, tacit extensions or renewal of the contract, arbitration clauses, or derogation from the competence of courts. 1342. Contracts made by means of forms or formularies. In contracts made by subscribing to forms or formularies prepared for the purpose of regulating certain contractual relationships in a uniform manner, clauses added to such forms or formularies prevail over the original clauses of said forms or formularies when they are incompatible with them, even though the latter have not been stricken out. The provisions of the second paragraph of the preceding article also apply.

NULLITY OF CONTRACT 1418. Causes of nullity of contract. A contract that is contrary to mandatory rules is void, unless law provides otherwise. A contract is rendered void by the lack of one of the requisites indicated in Article 1325, unlawfulness of causa, unlawfulness of the motives in the case indicated in Article 1345, and lack in the object of the requisites set forth on Article 1346. A contract is also void in the other cases established by law. 1419. Partial nullity. Partial nullity of the contract or the nullity of single clauses imports the nullity of the entire contract, if it appears that the contracting parties would not have entered into it without that part of its content which is affected by nullity. The nullity of single clauses does not import the nullity of the contract when, by operation of law, mandatory rules are substituted for the void clauses. 1421. Eligibility for action of nullity. Unless the law provides otherwise, nullity can be claimed by anyone who has an interest in it and can also be found, ex officio, by the court. 1422. Imprescrittibility of action of nullity. The action for a declaration of nullity is not subject to prescription, except for the effects of usucaption and of prescription of actions for restitution. 1423. Inadmissibility of validation. A contract that is void cannot be validated, unless the law provides otherwise. 1424. Conversion of void contract. A void contract can produce the effects of a different contract, of which it hs the requisites of substance and of form, whenever, considering the objective sought by the parties, it must be deemed that they would have wished it if they had known of the nullity. VOIDABLE CONTRACTS INCAPACITY 1425. Incapacity of parties. The contract is voidable if one of the parties was legally incapable of contracting. A contract made by a person incapable of understanding or intending is likewise voidable, when the conditions established by Article 428 occur. 1426. Subterfuge used by minor. The contract is not voidable if a minor, by subterfuge, has concealed his minority, but a simple declaration by him that he has reached majority does not prevent an attack on the contract. DEFECTS IN CONSENT 1427. Mistake, duress and fraud. A contracting party whose consent was given by mistake, extorted by duress or obtained by fraud, can demand annulment of the contract according to the following provisions. ACTION FOR ANNULMENT 1441. Eligibility. The annulment of a contract can be demanded only by those persons in whose interest it is established by law. The incapacity of a convicted person in a state of legal interdiction can be pleaded by any interested person. 1442. Prescription. The action for annulment is prescribed in five years. When voidability depends on a defect in consent or legal incapacity, the time runs from the day on which the duress ceased, the mistake or fraud was discovered, the interdiction or disability ceased, or the minor attained majority. In other cases the time runs from the day contract was made. Voidability can be pleaded by the defendant in an action for performance of the contract, even if the action for annulment is prescribed. 1443. Restitution against incapacited contracting party. If a contract is annulled for incapacity of one of the parties, such party is not bound to restore what he has received as performance to the other except to the extent to which it has benefited him. 1444. Validation. The contracting party entitled to sue for annulment can validate the voidable contract by a declaration containg a reference to the contract and to the cause for voidability thereof and a declaration of intention to validate it. A contract is likewise validated if the contracting party entitled to sue for annulment, knowing of the voidability, has voluntarily performed it. The validation has no effect if the person who does it is not in condition to validly conclude the contract. 1445. Effects of annulment on third persons. Annulment that is not based on legal incapacity does not prejudice rights acquired by third persons in good faith by a -gratuitous transaction, except for the effects of transcription of the petition for annulment.

1469 bis. Consumers' contracts. The provisions of this title apply to consumers' contracts, if not derogated by the consumption code or by other provisions more favorable for the consumer.