WIBOR: Same Name, Two Legal Regimes—What Can the Courts Examine?

Legal expert Krzysztof Szymański analyzes why the February 2026 ECJ ruling on WIBOR does not bar courts from examining loan agreements concluded before December 16, 2020.

What I Am Debating and What Claims I Am Defending

The loan agreement subject to the European Court of Justice ruling of February 12, 2026, in case C-471/24 was signed on August 1, 2019, amounting to PLN 413,436.69, with the 6-month WIBOR at 1.79 percent and a fixed bank margin of 1.85 percentage points. On that date, no entity possessed a Polish Financial Supervision Authority license to administer WIBOR, which GPW Benchmark S.A. only received seventeen months later on December 16, 2020. This seemingly technical detail forms the core dispute opened in “Bezpieczny Bank” by P. Grochowski and K. Koźmiński.

The commentators argue that since the Court reviewed WIBOR and formulated protection conditions, the path to questioning WIBOR clauses before common courts is closed. This text defends the opposite view—not because the ruling favors consumers, but because the commentators omit the conditional architecture of the judgment, particularly the temporal reservation in paragraph 3 of the operative part, assuming WIBOR was always uniformly regulated.

I defend three claims: the C-471/24 judgment confirms rather than excludes court jurisdiction over variable-rate clauses based on WIBOR; the favorable effect of points 2 and 3 is conditional upon EU BMR compliance at contract conclusion, which lacks administrative presumption for pre-December 2020 agreements; and courts may examine not just literal wording, but the rate’s adequacy, setting methods, and past procedures under Directive 93/13 and Article 385¹ of the Civil Code.

The Four Pillars of the Commentary

The commentators’ argument rests on four pillars: a systemic argument that the BMR regulation creates a closed regulatory circuit; the reading of point 2 that transparency rules impose no special methodology duties; the reading of point 3 as a general exclusion of unfairness claims based on index features; and extra-dogmatic criticisms of compensation law firms and market destabilization fears. The first three pillars omit the caveats attached by the Court, while the fourth is not a legal argument.

The Court ruled that Article 1(2) of Directive 93/13 does not exclude variable-rate clauses based on a benchmark and a fixed margin when national law leaves the choice of the benchmark and margin to the bank. The BMR regulates specialized entities rather than contractual balances, and benchmark rules originate from a private administrator, lacking legislative force.

Regarding transparency, while information duties are limited, the judgment uses cautious phrasing stating compliance “may indicate” transparency fulfillment. The final assessment belongs to the national court, and this entire rationale is anchored in the Mortgage Credit Directive regime applicable from July 22, 2017, omitting pre-date contracts.

Conditional Protection and the December 2020 Censure

Point 3 protects the index against unfairness claims based on its specific features only if the benchmark could be considered compliant with the BMR at the time of contract conclusion. This conditional phrasing, general clause, and isolating reservation leave room for national courts to assess whether compliance conditions were met and whether index features contributed to a significant imbalance.

Until December 16, 2020, WIBOR operated under a pure market self-regulation model without administrative authorization or public statutory oversight. The transitional tolerance of Article 51 of the BMR allowed temporary use of unverified benchmarks, which is not equivalent to positive verification of compliance.

Therefore, for pre-December 2020 contracts, the compliance presumption linked to an administrative license does not exist, leaving the condition to be proven under general rules. Subsequent regulatory adjustment cannot retroactively sanitize earlier procedural irregularities, as unfairness is assessed strictly according to the moment of contracting.