Your will is one of the most important documents that you can have. Sadly, many people delay preparing their wills until it's too late. In order for a person to make decisions about what happens to their property and interests (their estate) after they pass away they need to make a valid will. In order for their will to be valid, the person making the will (the testator) must: Have testamentary capacity; Have testamentary intention; Know and approve of the contents of the will; and Meet the formalities required by the law.