If at any time after buying a commodity a person realises that it has a defect, he can annul the transaction even if the seller is not prepared to accept it. The same rule applies to the other options for annulling a transaction. Ruling 2144.* In the following four cases, a buyer cannot annul a transaction due to a defect in the item nor claim the difference in price: 1. before buying, he knows about the defect in the item; 2. after buying, he accepts the defect; 3.
at the time of the sale, he waives his right to annul and take the difference in price; 4. at the time of the transaction, the seller says, ‘I am selling this item with all the defects it has’. However, if he specifies a particular defect and says, ‘I am selling this item with this defect’, and later another defect is discovered, the buyer can return the item owing to the defect that the seller did not specify. And in case he cannot return it, he can claim the difference in price.