Ineffectiveness and invalidity of a legal transaction
From the construction of the ineffectiveness of the bankrupt's activity, the construction of the invalidity of the legal act should be distinguished due to (a) the conflict of action with the law (act), (b) the purpose of the act of circumventing the law (act), (c) the contradiction of activities with the rules of social coexistence (art. 58 § 1 and 2 of the Civil Code). In the judgment of the Court of Appeal in Krakow of January 16, 2015, I ACa 1493/14, it was raised that "annulment is the most severe sanction of a defective legal act, whereas construction ineffectiveness of a relative legal act is that it protects a person whose satisfaction of just claims has been excluded by carrying out a legal action with a person who is not the owner of the thing. Such an action is therefore important because ineffectiveness is a sanction not so much due to an irregularity inherent in the legal act itself, which is the essence of absolute invalidity, but due to the intentions of people who took the action. Recognition of an activity as ineffective is determined by the conditions and circumstances in which the action was taken, not the irregularities inherent in it. Therefore, it is a sanction because the legal act was concluded in a specific situation, and not for the reason of sanction of nullity, that it was wrong and did not meet the conditions (premises) of regularity. "The effect of the invalidation is that ( if, in connection with the act, the benefits were fulfilled, in other words, the legal act was of an incident nature) that the party who received the benefit should issue the benefit in kind, and if it was not possible, then it is obliged to return its value (art. 405 of the Civil Code in relation to Article 410 of the Civil Code - condictio sine causa). The obligation to issue the subject of the benefit in kind or a replacement duty to return the value of the benefit rests on each page of the invalid legal relationship that received the donation. The effect of the ineffectiveness of legal action in the area of bankruptcy law is that "what is lost or not entered into by the bankruptcy estate is transferred to the bankruptcy estate, and when the transfer in nature is impossible, the equivalent in money should be paid to the bankruptcy estate" (Article 134 (1) pu). In turn, so-called The "counter-performance" of a third party (and in principle the donation made by a third party) shall be reimbursed to the person if he is in the mass of bankruptcy separately from other property or if the mass is enriched. If the benefit is not refundable, the third party may claim a claim in the bankruptcy proceedings (Article 134 paragraph 2 point). It can be argued that the scheme of the construction of the effects of the nullity and ineffectiveness of a legal act in the area of bankruptcy law is similar. At the same time, it should be remembered that in the light of the provisions of the Civil Code, the effects of the ineffectiveness of a legal act were regulated in another way (Article 532 of the Polish Civil Code). It should be further emphasized that an absolutely invalid legal act is null and void from the moment it was made, each court should automatically consider the state of nullity of the legal action. In the case of ineffectiveness, the situation is slightly different.
 M. Gutowski, Bezskuteczność czynności prawnej, Warszawa 2013, p. 41
 P. Mostowik, in: System prawa prywatnego, Prawo zobowiązań – część ogólna, A. Olejniczak (editor), vol. 6, Warszawa 2009, p. 308.
 . R. Adamus Kilka uwag o zasadzie pierwszeństwa zaspokojenia wierzyciela na podstawie art. 532 KC, Monitor Prawniczy 2013, no 15, p. 799