A evolução do princípio da boa-fé no Direito Fiscal

: uma expansão em curso

Abstract

The privatization of Tax Law and its progressive complexity and instability has made its application more demanding and unpredictable. For that reason, it is of the utmost importance seeking the interpretation that the Tax Authority makes of the law, rather than trying to observe the law itself. Consequently, the principle of good faith, which is legally represented by the advance ruling and the generic guidelines, has been gaining relevance against abusive and unpredictable behaviours of the Tax Authority, protecting the taxpayers against serious legal consequences. This dissertation will, in first place, analyse the advance ruling and the generic guideline regime and its fundamental aspects. It will then demonstrate the field of application of the principle of good faith, the occasions when its invocation is legitimate, as well as its effects.

Date of Award	19 Nov 2025
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Tomás Tavares (Supervisor)