Made in writing and registered by the competent official . These contracts must be made in writing with the relevant signatures affixed thereto , and they must also be registered with the official concerned . Examples if such contracts are : sale of immovable property ( land , house , land attachment or its component parts and all rights concerning land rights ) , or the sale of some types of movables such as a floating house , beast of burden , or the mortgage of the said immovable and movable properties . All these contracts , if not made in writing and registered with the concerned officials , are void according to the law . An exception ti this is a lease agreement of an immovable for a lease period of over 3 years . If such an agreement is not in writing ang registered with the official , the contract shall be enforceable for only 3 years .