In the countries belonging to the OHADAC, in both civil law and common law, it is commonly accepted that no one can be obliged without their consent and that the consent is formed by the offer and the acceptance of said offer. This is the habitual model to form and conclude contracts. The offer and acceptance model exists in the Caribbean countries governed by civil law and frequently it is expressed in their civil codes (Articles 1.009 and 1.010 of the Costa Rican Civil Code; Article 311 of the Cuban Civil Code; Article 1.521 of the Guatemalan Civil Code; Article 6:217 of the Dutch and Suriname Civil Code; Article 1.553.1º of the Honduran Civil Code; Articles 1.804-1.811 of the Mexican Civil Code; Article 1.113 of the Panamanian Civil Code; Article 1.214 of the Puerto Rican Civil Code) or in their commercial codes (Articles 845 to 863 of the Colombian Commercial Code; Article 54 of the Cuban Commercial Code; Article 718 of the Honduran Commercial Code; Article 83 of the Nicaraguan Commercial Code; Articles 201 of the Panamanian Commercial Code and 1.113 Civil Code, Article 272.1 of the Santa Lucian Commercial Code, Article 110 of the Venezuelan Commercial Code). Consent is also necessary in the countries belonging to the common law legal tradition. Although the central idea of the contract not the obligation itself, but the exchange of promises through consideration, consent is expressed through reciprocal promises [Section 2 (1) English Sale of Goods Act; Section 3 (1) Sale of Goods Act of Antigua and Barbuda; Section 6 (3) Sale of Goods Act of Bahamas; Section 6 (3) Sale of Goods Act of Montserrat; Section 3 (1) Sale of Goods Act of Belize; Sections 2 and 6 (3) Sale of Goods Act of Jamaica; Section 3 (1) Sale of Goods Act of Trinidad and Tobago).

The bilateral model of offer and acceptance has been formulated in the CISG (in force in Colombia, Cuba, Honduras, Dominican Republic, Saint Vincent and the Grenadines and Guyana). Articles 14 to 24 regulate the requirements that the offer and the acceptance must satisfy in order to conclude the contract, although they do not expressly mention the consent mechanism through the offer and the acceptance. The conclusion of contracts through offer and acceptance is regulated in Article 2.2.2 UP and also in Article 30.2º CESL.

However, the PECL and the DCFR (Article II-4:201) seem to have deviated from the bilateral model and it is stated in Article 2:101 that the formation of the contract requires only that the parties declare their intention to be legally bound and have reached a sufficient agreement. But, the bilateral scheme has not been abandoned, although Article 2:211 PECL specifies that the rules relating to offer and acceptance will be applied with the appropriate adaptations even though the process of contract formation cannot be analysed into offer and acceptance.

Example 1: If a US businessman offers a Jamaican businessman a car for $ 18,000 and the Jamaican businessman agrees, a valid contract is concluded and the offer and the acceptance can be identified without problems. In other more complicated contracts, with long negotiations, it is necessary to consult the exchange of documents between the parties to see if they have come to an agreement.

Some countries do not mention offer and acceptance, either in the civil code or in the commercial code. This is the case of France and the Dominican Republic (Articles 1.101 and 1.108 Civil Code) or Haiti (Articles 897 and 903 Civil Code), which consider the contract as an agreement that requires consent, capacity, determined object and legal cause. However, the Draft project of reform of the French law of obligations of 2013 reserves Chapter 2 to the conclusion of the contract, using the offer and acceptance model (Articles 13-34).

To demonstrate the existence of contractual consent or an agreement of intentions requires the application of rules on the interpretation of the contract included in section 1 of Chapter 4 of these Principles, which are applicable, mutatis mutandis, to unilateral declarations of intention. To this end, the comments to the rules of said Chapter, particularly those that refer to the diversity of comparative systems and to problems raised by subjective and objective tendencies of interpretation. In practice, as analysed in commentaries on Chapter 5, although civil law and common law systems have opposing principles, they coincide in the objective interpretation of declarations in line with reasonable criteria, in the light of a context taken in a broad sense.

Example 2: If during a meal in a restaurant, a Dominican businessman A offers a Haitian businessman B a machine for a good price and the businessman B gives $ 1000 as a deposit, the contract will have been concluded, although A's intention was to play a joke on B, since B does not know that A has no intention to be obliged because the proposition and any reasonable person could have believed that A has formulated a real contractual offer.