WIBOR litigation, part 2: Can basing variable interest rates on WIBOR be deemed an abusive clause? | In Principle

Some consumers are attempting via the Polish courts to undermine provisions in credit agreements setting variable interest rates on the basis of the WIBOR benchmark. They hope that the courts will hold these clauses to be impermissible under Civil Code Art. 385¹. This would allow their credit agreement as a whole, or the specific WIBOR provisions, to be set aside. But does Polish law empower the courts to examine the alleged abusiveness of such provisions?

Under Civil Code Art. 385¹ §1, “Provisions of a contract with a consumer and not individually negotiated shall not be binding on the consumer if they frame the consumer’s rights and obligations in a manner contrary to fair practice, grossly infringing the consumer’s interests (impermissible contractual provisions). This does not apply to provisions defining the parties’ principal consideration, including price or remuneration, if they are worded unambiguously.”

This provision directly corresponds to:

• Art. 3(1) of Council Directive 93/13/EEC of 5 April 1993 on unfair terms in consumer contracts, which provides, “A contractual term which has not been individually negotiated shall be regarded as unfair if, contrary to the requirement of good faith, it causes a significant imbalance in the parties’ rights and obligations arising under the contract, to the detriment of the consumer,” and
• Art. 4(2) of Directive 93/13/EEC, which provides, “Assessment of the unfair nature of the terms shall relate neither to the definition of the main subject matter of the contract nor to the adequacy of the price and remuneration, on the one hand, as against the services or goods supplie[d] in exchange, on the other, in so far as these terms are in plain intelligible language.”

And although not directly reflected in the Polish regulations, Art. 1(2) of Directive 93/13/EEC is also key for determining the scope of application of Civil Code Art. 385¹ §1 and the corresponding provisions of the directive. Under that provision, “The contractual terms which reflect mandatory statutory or regulatory provisions and the provisions or principles of international conventions” are not subject to the directive. This follows from the assumption stated in the preamble to the directive that “the statutory or regulatory provisions of the Member States which directly or indirectly determine the terms of consumer contracts are presumed not to contain unfair terms….” This assumption applies to regulations of mandatory applicability, as well as regulations of optional applicability (i.e. which the parties are allowed to contract around), so long as the parties have not made any changes to them (M. Korpalski & W. Nowak, commentary on Art. 1, in Unfair terms in consumer contracts: Commentary on Council Directive 93/13/EEC (Warsaw: Lex, 2024)).

For this reason as well, in litigation over WIBOR (the Warsaw Interbank Offered Rate), the Polish courts will often verify at the outset whether the contractual provisions in question reflect applicable statutory or regulatory provisions. Whether the court is allowed to review the alleged abusiveness of a clause at all depends on the answer to this question.

Consumer mortgage loans

According to the dominant view in the rulings of the Polish courts, in the case of consumer mortgage credit concluded under the Mortgage Credit Act (Act on Mortgage Credit and Supervision of Mortgage Credit Brokers and Agents), basing the interest rate on WIBOR arises out of provisions of law.

This is because under Art. 29(2) of the Mortgage Credit Act, if the parties have not agreed on a fixed rate of interest, the manner of setting the interest rate is determined as the value of a benchmark and the margin established in the mortgage credit agreement. In turn, under Art. 4(28), a benchmark is an index referred to in the Benchmark Regulation or BMR (Regulation (EU) 2016/1011 of the European Parliament and of the Council of 8 June 2016 on indices used as benchmarks in financial instruments and financial contracts or to measure the performance of investment funds).

Under the BMR, WIBOR has the status of a critical benchmark. This leads to the conclusion that Polish lawmakers provided for application of WIBOR in the interest rates on consumer mortgage loans, and thus these provisions are not subject to review for abusiveness (see judgments of the Łomża Regional Court of 21 June 2024 (case no. I C 405/23), Gdynia District Court of 30 September 2024 (case no. I C 654/23), and Piotrków Trybunalski Regional Court of 3 April 2024 (case no. I C 209/24), and of the Warsaw Regional Court in cases no. XXV C 192/23, IV C 1097/23, IV C 999/23 and IV C 1160/23).

Other consumer credit

However, these conclusions cannot easily be carried over to other types of credit issued to consumers. Thus it is worth considering what in that case might be the result of an examination of the abusiveness of clauses in other credit agreements incorporating WIBOR as the basis for variable interest rates.

The examination of whether a contractual clause is impermissible should begin with determining whether the clause was individually negotiated (see Civil Code Art. 385¹ §3 and Art. 3(2) of Directive 93/13/EEC). In nearly all consumer credit agreements, the provisions for determining the level of variable interest rates are not individually negotiated. Rather, the interest-rate mechanism is an element of the bank’s offer over which the consumer has no real influence. Most often, the interest-rate mechanism is also part of a contractual template proposed to the consumer by the bank. Thus the condition of lack of individual negotiation is met, and an examination of abusiveness is potentially allowed.

The next step is to determine whether the clause defines the parties’ principal consideration and was worded unambiguously (see Civil Code Art. 385¹ §1, second sentence, and Art. 4(2) of Directive 93/13/EEC).

In the case of credit agreements and clauses on the interest rate charged by the bank, the prevailing view in the decisions from the Polish courts to date is that a variable interest rate clause defines the principal subject of the parties’ agreement (i.e. it is potentially examinable for abusiveness). As the Gliwice Regional Court reasoned in the judgment of 8 July 2024 (case no. I C 308/24), “It appears that a variable interest rate clause defines the main subject matter of the contract within the meaning of Art. 4(2) of Directive 93/13/EEC. The variable interest rate clause relates directly to the borrower’s principal consideration, because a credit agreement is always a transaction for paid consideration” (see also Łomża Regional Court judgment of 21 June 2024 (case no. I C 405/23) and Warsaw Regional Court judgment of 23 October 2023 (case no. XXV C 192/23)).

It should then be determined whether the variable interest rate clause based on WIBOR was worded unambiguously (see Civil Code Art. 385¹ §1, second sentence, and Art. 4(2) of Directive 93/13/EEC). If it is unambiguous, there are no grounds for examining the abusiveness criteria set out in the first sentence of Civil Code Art. 385¹ §1 or Art. 3(1) of Directive 93/13/EEC.

Under the case law from the Court of Justice of the European Union, in assessing whether a contractual provision is plain and intelligible, the linguistic layer should be considered (a bank using a contractual template should draft it in simple, clear and understandable language), but also whether the bank has complied with its informational obligations to the consumer so that the consumer can estimate the economic consequences flowing from the transaction (T. Nowakowski, “Abusiveness of variable-interest clauses based on a benchmark under the case law of the Court of Justice,” Europejski Przegląd Sądowy no. 5/2025, p. 16).

The rulings to date from the Polish courts mostly recognise that the banks have fulfilled these conditions for clarity, considering such arguments as:

• The universal access to information on WIBOR, published for example of the website of the benchmark’s administrator
• Simulations of credit repayment instalments, which the banks have presented to consumers
• The banks’ compliance with the recommendations of the Polish Financial Supervision Authority (KNF) on the rules for informing borrowers of the risk arising from the use of WIBOR
• Declarations signed by consumers acknowledging their understanding and acceptance of the risk of a change in interest rates (T. Nowakowski, “Overview of current rulings in WIBOR cases,” LEX/el. 2025).

The case law from the Court of Justice has also confirmed that banks are exempt from the duty to provide consumers with commonly and easily accessible information about a benchmark (Nowakowski, “Abusiveness,” p. 16).

However, whether language is plain and intelligible is evaluated individually in the case of each credit agreement. Therefore, even if in practice WIBOR-based variable interest rate clauses generally meet the criterion of being unambiguous, in individual cases—if the bank has not met its informational obligations—the alleged abusiveness of such clauses can be examined. Nonetheless, it should be stressed that in the cases decided to date by the Polish courts, this stage is usually not reached.

And even if an ambiguous WIBOR-based variable interest rate clause is examined for abusiveness, it is unlikely to be found abusive in light of the existing case law from the Court of Justice, which indicates significant factors preventing WIBOR-based clauses from being found to be abusive.

One factor is that for determining variable interest rates, for many years there was no viable alternative for the WIBOR benchmark existing on the Polish market. This means the bank can assert that, based on the law, it acted in good faith, which excludes a finding that the clause was abusive (Nowakowski, “Consequences,” p. 19). Another factor is tied to the method adopted by the Court of Justice which requires a comparison between the variable interest rate mechanism in the challenged agreement, against the method most commonly used on the market (Nowakowski, “Abusiveness,” p. 19). Since WIBOR is in fact the most commonly used benchmark in credit agreements in Poland, it would be hard to justify the claim that if the consumer had the possibility of individually negotiating the terms, the consumer would not have accepted the use of WIBOR in the specific contract (Nowakowski, “Abusiveness,” p. 20).

Summary

All of this leads to the conclusion (also in light of the rulings to date by the Polish courts) that regardless of the stage of examination reached by the court, WIBOR-based variable interest rate provisions should not be found to be impermissible under Civil Code Art. 385¹ §1 or the corresponding Art. 3(1) of Directive 93/13/EEC.

In the case of consumer mortgage loans (issued under the regime of the Mortgage Credit Act), contractual provisions using WIBOR as the basis for calculating variable interest rates cannot be reviewed for abusiveness in light of Art. 1(2) of Directive 93/13/EEC, which bars examination for abusiveness of provisions that “reflect mandatory statutory or regulatory provisions.” Here, the Mortgage Credit Act (in connection with the BMR) is the immediate basis for applying WIBOR in such agreements.

In the case of other credit agreements with consumers, the examination for abusiveness should end either at the stage of determining whether the clause is unambiguous (a finding that the bank met the conditions for clarity ends the matter), or at the stage of examining the criteria for the abusiveness of an ambiguous clause defining the main subject matter of the contract, which category includes variable interest rate clauses (the risk that such a provision will be found to be abusive is extremely low).

Mateusz Kosiorowski, adwokat, Anna Szczęsna, Dispute Resolution & Arbitration practice, Wardyński & Partners