The article examines
the extent to which courts and tax authorities should rely on the outcomes of
prior judgments, particularly in the context of tax law. First, it explores how
final court judgments can be binding in subsequent related proceedings in some
countries. Second, it discusses how the right to a fair trial limits the
ability to invoke previous court judgments in ongoing proceedings without
allowing parties to conduct evidentiary hearings on facts adjudicated in those
prior judgments. Third, the authors analyse situations where final judgments
should be considered binding due to the principles of legal certainty and the
presumption of innocence. Finally, they discuss whether a breach of EU law
provides grounds to refrain from applying the res judicata principle. The
article concludes that while the binding nature of court judgments presents a
multifaceted legal challenge, the core principles of fairness, legal certainty,
and the presumption of innocence must be respected. The interplay between these
principles underscores the need for careful consideration and potential
refinements in national legislation and judicial practice to ensure that the
pursuit of justice aligns with fundamental rights.