The regularity and the identification of the data in an accounting document are fundamental characteristics of this type of writing. To be able to administer a city, a kingdom or any private patrimony, a large amount of data has to be used and recorded. My paper wants to analyze the notarials forms used in accounting registers of the city of Bologna from the end of the 13^th century to the end of the 14^th century. The city of Bologna, in fact, offers a particularly favorable field of study. The Archivio di Stato di Bologna keeps a considerable amount (relative to the time) of fiscal sources. This paper will allow us to understand their use for accounting purposes, how these forms have evolved. The study of this sources will enable us to understand the use of accountings forms (in particular their changes and continuity) as it was made by notary from Bologna, which, as we know, was taken as an example in many European areas.