EN
The author discusses the selected problems related to the vague terms and general clauses in the personal income tax laws in Poland, with particular attention given to the term of subject of taxation. The author overviews the requirements for the use of vague terms and explains the rationale behind it, which is, inter alia, the need for greater flexibility of interpretation. The author claims that the legislators do not always properly use vague terms in the tax law, and their complexity and overload can lead to dilemmas. Some recommendations on the proper use of such terms in personal income tax legislation are given.