In the entry into force of the law, it is normally stated when the tax laws will enter into force. As a rule, tax laws cannot be applied before the effective date. Reversal of the laws covers a period before the effective date and as a rule, the laws cannot be executed. Rules governing people's behavior should provide them with security. The principle of non-retroactivity of tax laws is a requirement of the principle of legal security; the application of a new tax law in the past to increase taxpayers' tax burden adversely affects trust in the state and the law. However, it is seen that the laws applies the laws include real retroactivity of a law and , non-real retroactivity of a law These applications are especially economic crises, the fight against inflation and war and so on. it can be done for legitimate or justified reasons such as taxing unfair gains in extraordinary situations.
The Principle of Non-Retroactivity of Tax Laws, Real Retroactivity of a Law, Non-Real Retroactivity of a Law.