Article 500 of Civil Code

1 - The price shall be payable immediately upon completion of the sale, unless an agreement or custom provides otherwise. - If anyone interferes with the buyer on the basis of a right predating the sale, derived from the seller, or resulting from his act, or if there are serious grounds to fear eviction from the thing sold, the buyer may, Law Index 1008 Home Page Decree-Law No. 67 of 1980 AD Promulgating the Civil Code unless prevented by a contractual term, withhold the price until the interference ceases or the risk of eviction disappears. However, the seller may in that event demand payment of the price upon providing a surety. 3- The preceding paragraph shall apply if a defect appears in the thing sold.