The buyer of real estate has to pay the sale price by the timing prescribed by the sale and purchase agreement. The timing of payment is usually simultaneous with that of delivery of the property by the seller.*Civil Code(Defense of Simultaneous Performance)Article 533 A party to a bilateral contract may refuse to perform that party's own obligation until the other party tenders the performance of that other party's obligation (including the performance of an obligation to compensate for loss or damage in lieu of the performance of an obligation); provided, however, that this does not apply if the obligation of the other party is not yet due.