The dichotomy between the Tax Constitution and its infra-constitutional realization by the Tax Administration and the Tax Courts praxis

The Portuguese Republic Constitution establishes in articles 103, 104 (the so-called “Tax Constitution”) and 165, no. 1, i) the main tax principles that must govern the Portuguese tax system and consequently the tax legislation in Portugal. The income, consumption and property tax regimes set out in infra-constitutional legislation, namely on the respective tax codes, must abide the general tax principles set forth in the Tax Constitution. Nevertheless, that is not always the case, as the infra-constitutional legislation is not duly harmonized with these principles and establishes rules that are not compliant with the Tax Constitution.

In addition, the Tax Courts and the Tax Administration have been interpreting and applying these infra-constitutional provisions without considering, in general, if the same are, or not, in breach of the Tax Constitution.

The main goal of this study is to identify all legal provisions for income, consumption and property taxes purposes that do not comply with the Tax Constitution principles and determine what adequate avenues are to be followed to allow the harmonization of the Tax Constitution with the infra-constitutional legislation to guarantee the legal certainty of the taxpayers, either individuals or companies.

This study also aims to draw a comparative analysis between the Portuguese and European tax systems, namely Spain as well as between the Portuguese and the Angolan tax systems considering the historical influence of the portuguese constitutional tax law and practice in the angolan tax system.

This project will be coordinated through CIDEEFF by a team comprising integrated researchers from the Centre, as well as lecturers from the Faculty of Law of the University of Lisbon, a research institute and/or Faculty of Law from an EU Member State, namely Spain, and from a third country, namely Angola, still to be determined.

Research Team:
Prof. Dr Sónia Martins Reis
Prof. Dr Paulo Marques
Dr Tiago Barbosa
Dr Miguel Teles

Keywords:
Fiscal Constitution
Sub-constitutional Tax Legislation
Income Taxes
Consumption Taxes
Wealth Taxes
Practice of the Tax Administration and Tax Courts

Duration: 2025–2029
Status: Ongoing