The paper tries to analyze methods for individual age certification in 13th-14th Italian city-states, where civil life depended on thresholds of age, which the principal one was of course the age of majority, such as everywhere at anytime. Legal sources as Artes notariae and jurists as Bartolo and Baldo confronted with judiciary documents and normative sources put evidence on two ways of certification, the aspectus corporis performed by the judge and the denumeratio annorum proved by oath and witnesses, which allowed the judge to pronounce its sentence, the instrumentum annorum.