Failure to comply with the general obligation to segregate municipal waste has the consequence of imposing a municipal waste management fee at a sanctioning rate. The aim of the study is essentially a critical commentary on the complete disregard by the Supreme Administrative Court of the extra-linguistic rules of interpretation of Article 6ka of the Act on Maintaining Cleanliness and Order in Municipalities of 13.09.1996. The interpretation applied by the Supreme Administrative Court (SAC), based exclusively on the directives of linguistic interpretation, leads to the conclusion that demonstrating even one case of non-compliance with the adopted principle of waste segregation entails the obligation to impose a fee on the interested entity at the rate applicable to non-selective collection of waste. The position presented by the SAC contradicts the will of the legislator expressed in the justification of the Act introducing the aforementioned provision and may breach the principle in dubio pro tributario. The study used a dogmatic-legal research method. The analysis covered legislation and legislative materials, as well as, additionally, the achievements of doctrine and the jurisprudence of administrative courts.