The accounting reform introduced in Italy by Law 196 of 2009 has, among its objectives, the harmonization of accounting. It defines a series of rules that make possible to produce data ready to be used both for the administrative purposes of government and for production of public finance statistics. To achieve this goal the decision was to adopt, in the administrative area of public budgets - for all phases of preparation, management and reporting - the classifications of official statistics, according to the national accounts’ rules. The introduction of the new classifications was significant and required a four-year experimental process for the Italian local authorities. The expenditure classification by Missions and programs, associated with the international COFOG1 classification, is the main objective of this document also taking into account that a glossary was prepared that defines in detail the content of each mission, program and the corresponding COFOG. The budget data for the five-year period 2016–2020 show interesting results that confirm both the importance of the direct adoption of the standard classifications of the national accounts into the budget and the ability of the local authorities to improve over time, as evidenced by the increasing quality of the data in the last two years, compared to the 2016 data, the first year the accounting reform was applied to all local authorities.