The sale is a bilateral, onerous contract whereby the seller undertakes to transfer to the buyer the ownership right over the property, and the buyer is bound to pay the price and obtain the property. The sale is governed by Art. 183 and the following of the Obligations and Contracts Act (OCA).
Pursuant to Art. 18 of the OCA, the contracts for transfer of ownership or for establishment of other real rights over immovable property must be executed by means of a title deed. The transaction of a purchase and sale of real estate which is not executed in the statutory form (title deed) is deemed void under Art. 26, para. 2 of the OCA. The seller's obligation is to deliver the property and to receive the sale price and the buyer's obligation is to pay the sale price and obtain the property.