The aim of this article is to examine the scope of freedom in tax planning in relation to the restrictive nature of determining the appropriate transaction. The author defends two theses. First, a taxpayer, when planning their actions, enjoys a relatively broad scope of freedom, defined by the hypothesis of the anti-tax avoidance clause. To a limited extent, their actions may even exhibit signs of abusiveness. Second, when tax abuse, as understood under Article 119a § 1 of the Tax Ordinance, occurs, this freedom becomes significantly restricted. The Head of the National Revenue Administration, when determining the appropriate transaction, must, in principle, indicate a single transaction that is free of abusiveness and rational, with this rationality being relativized to the specific circumstances of the given entity.

The subject of analysis in the article is the competence of the tax legislator to stop tax depreciation in the light of the principle of acquired rights and protection of interests in progress, based on the example of legislative changes introduced from January 1, 2022. The aim of the article is to prove that in the event of discontinuation of real estate depreciation, the correct model of constitutional control is not the principle of protection of acquired rights, but the principle of protection of interests in progress. Discontinuation of real estate depreciation is in principle incompatible with the principle of protection of interests in progress, which, however, does not apply to legislative changes relating to private rental. In this case, the legislator decided to introduce a systemic change — the elimination of one form of taxation and taxation of private rental only on the basis of a lump sum on reported income, which excludes the possibility of further depreciation.