This paper verifies the applicability of the digital audit in service companies, contributing to the immediate improvement of tax management. This research is considered relevant due to the opportunity to specialize the Auditors in carrying out their tasks and in other fields of endeavor, prominently in public expenditure. Through a mathematical model - Newcomb-Benford's law -irregularities could be identified in companies, as an important tool to plan audits. This interdisciplinary research is also important due to the unedited application of this method to Service Tax. The case study strategy was used, with detailed analyses of companies inspected in 2005 and 2006. The qualitative approach was applied to better understand the functioning of the Supervision Department's organizational structure, collecting data through documentary analysis and unstructured interview. Using the quantitative approach, adherence to the model was verified, which signaled deviations. The documentary analysis, interviews and model tests acted in a constant information triangulation process. The results suggest: adherence to ISS supervision model; importance of putting the method in practice in other areas; urgent need to promote changes in forms and rules to audit firms, as well as in the dissemination of these results to Brazilian cities, mainly because no new investments are demanded, in view of scarce resources in public administration. Finally, a national research agenda is suggested to enhance tax management.
Digital Audit of ISS; Model Newcomb-Benford's law; Fundraising Increment
