Taxation principles and property rights within the framework of Constitutional Court and ECtHR decisions

Taxation is imposed under coercion to meet public expenditures based on public power. In addition to imposing obligations on the taxpayer by using this absolute power, the state ensures the protection of the rights granted to the taxpayer and to prevent the arbitrariness of the administration through the law. Although Article 73 of the Constitution constitutes the basis of taxation, Articles 2, 10, 13, 20, 35, 36 of the Constitution are also the source of direct or indirect taxation principles. The ECHR does not contain provisions directly related to taxation principles. However, through its articles dealing with the right to property and the right to a fair trial, the ECtHR has observed that the principle of legal security is violated by tax interventions, and the proportionality, foreseeability, legality and non-retroactivity of tax interventions in the public interest are checked. It has been observed that the tax principles in the jurisprudence of the Constitutional Court, which we have examined, are also common in the jurisprudence of the ECtHR, the principle of legality, the principle of proportionality, the principle of equality, and the principle of legal security. It has been determined that there are common jurisprudences that interpretation in taxation is legal if a foreseeable result is reached within the legal limits, that retroactivity is not legal unless it is in favor of the taxpayer, and that property can only be restricted by law and proportionally to the public interest.