The regulation of the contractual clause known as lex commissoria raises many doubts in the context of the statutory and contractual right of withdrawal from a contract under the Civil Code. It is not a structurally complex provision; it is sufficient to meet a few specific conditions – a reservation in the contract in the event of the debtor’s delay, when the obligation has not been performed within a strictly defined time limit. In practice, however, this is usually an “accidental” clause, as the parties rarely consciously include it in the contract. This is because, from the creditor’s point of view, it is more advantageous to stipulate a contractual right of withdrawal, but the invalidity of such a provision due to the lack of a time limit for this right means that it is necessary to consider whether we are dealing with legis commissoriae. It is important to note that this is an independent construct, functioning independently of the provisions regulating the two aforementioned rights of withdrawal from the contract.

Recently, the right of retention (ius retentionis) has undergone a kind of renaissance, which is due to the nature of disputes arising against the background of credit agreements linked to foreign currency (especially CHF) – indexed and denominated credit agreements. The filing of a plea of retention by the party is supposed to result in the withholding of the benefits received from the borrowers until the borrowers either offer to return the benefits received from the banks under the credit agreements or secure claims for their return. However, in the case of reciprocal monetary benefits, the right of retention does not apply, as the benefits of both parties are of a single nature and therefore they are entitled to a more far-reaching right, namely the possibility to make a declaration of set-off. This applies in particular to the mutual benefits of the parties under an invalid credit agreement, including those linked to foreign currency (on the assumption that the credit agreement is a reciprocal agreement). This is where the consumer protection aspect of Directive 93/13, which has been very strongly emphasised in the CJEU's case law, comes in.

One of the basic assumptions of the amendment to the Code of Civil Procedure from 4.07.2019 is to counteract the parties' abuse of procedural law, so making the rights provided for in the provisions of use incompatible with the purpose for which they were established (Article 41 of the Code of Civil Procedure). The legislator significantly expanded the scope of the sanctions, which can be applied by the court in the event of abuse of procedural law by a party. The legislator rightly considered that disloyal and dishonest behavior of a party, especially those affecting the unjustified extension of proceedings, should be incriminated in a much broader scope than before. Although the introduction of new trial measures aimed at implementing the principles of loyalty in civil proceedings should be assessed positively, their structure raises serious doubts from the theoretical and practical point of view. The aim of the article is to present the practical aspects of applying the measures provided for in Art. 226² § 2 of the Code of Civil Procedure.

Interest on trial costs is a new regulation in the Polish civil procedure. The solution adopted by the legislator, although going in the right direction, raises both theoretical and practical doubts. The main problem is to determine whether the interest should be included in the judgment closing the case, as part of the costs of the trial, or whether it's awarded in some other form. Answering this question implies further problems, particularly related to the challengeability of such a decision. The analysis of the provisions allows to conclude that interest forms part of the costs of the process, with all the consequences.