Retroactive Tax Legislation in View of Article 1 First Protocol ECHR

One of the principles derived from the rule of law is that laws should not be retroactive. Taking into account that the rule of law is inherent to the ECHR, the question arises as to how the ECtHR judges retroactive tax legislation. This question is particularly emerging since retroactive tax legislation is not uncommon in the Member States. This contribution scrutinezes in which way the ECtHR tests retroactive tax legislation for compatibility with Article 1 First Protocol ECHR, and which basic guidelines with respect to the testing of retroactive tax legislation can be deducted from the case law of the ECtHR