WIBOR becomes history: Will the transition to WIRF lower your installment?

Replacing WIBOR with the WIRF index aims to make debt costs more realistic; however, the actual change in installment amounts depends on the terms of the annexes signed from 2025 onwards and the guidelines stemming from the CJEU opinion of September 11, 2025. Borrowers expecting an automatic reduction in financial burdens should verify their expectations against market realities. The transition to the new index is a technical process that banks are using to renegotiate margins, which in many cases may lead to an increase in the installment, despite a theoretically lower base index.

Will the index change actually lower the loan installment?

The debate over the successor to WIBOR has been ongoing since June 2022, when WIRD and WIRF were first publicly identified as viable alternatives to rates based on future interest rate valuations. WIRF, as an index based on actual transactions, is intended to reflect the real cost of obtaining money for banks. However, in credit economics, the mathematics of the index is only one variable in the loan cost equation. The second, often ignored by clients, is the bank margin.

Banks in Poland, preparing for the phase-out of WIBOR scheduled for December 2027, do not intend to give up their current level of profitability. At the moment of signing an annex changing WIBOR to WIRF, financial institutions have the right to recalculate the margin. If a bank decides that the base margin does not compensate for its risks or operating costs in the new model, it may adjust it upward. In practice, this means that a borrower switching to the theoretically "cheaper" WIRF may receive an offer with a higher margin, which in the final analysis will keep the installment at the current level or even increase it.

The banking sector argues that such a rapid change in reference rates generates systemic risk. The CEOs of the largest banks emphasize that a sudden recalculation of millions of loan agreements without securing the interests of the institutions would disrupt balance sheet liquidity. This position is a direct response to concerns about the stability of the sector. For the consumer, however, it means that banks will strive to maintain the status quo regarding interest income. The change of the index is not an act of financial charity, but a legal necessity that banks are turning into a tool for managing their own risks.

Traps hidden in bank annexes

Since the beginning of 2025, banks have been conducting an intensive campaign encouraging clients to sign annexes. Clients receive correspondence suggesting that a lack of signature may complicate debt servicing or expose them to legal uncertainty. This approach raises objections from experts dealing with consumer rights protection. Under time pressure, borrowers often sign documents whose consequences go far beyond the mere change of the reference index.

In the annexes offered by banks, the most common risk is the waiver of claims clause. Banks are trying to protect themselves against future lawsuits by introducing provisions that prevent the client from challenging the margin set at the time of the index change. By signing such a document, the borrower loses the right to raise objections regarding irregularities in the method of calculating interest before the transition to WIRF. This is a trap that could block the path to recovering overpaid funds in the future.

Another threat is the method of recalculating the margin. Banks use various mathematical algorithms that seem neutral at first glance. However, a thorough technical analysis shows that the margin can be adjusted in a way that is unfavorable to the client if the bank adds a so-called systemic adjustment cost. Experts warn that hundreds of thousands of Poles may have unknowingly signed documents that will lock in unfavorable financial conditions for years. It is worth noting that the lack of a signature on an annex does not at all mean an automatic termination of the loan agreement, as is sometimes suggested by advisors at bank branches.

The CJEU opinion of September 11, 2025, as a turning point

The opinion of the CJEU Advocate General of September 11, 2025, provides the foundation for further assessment of the legal effects of the index transformation. This document defined how banks should treat historical WIBOR rates in their relationship with the client. Financial institutions that sent out mass proposals for annexes found themselves on the defensive. EU judges indicated that consumer protection outweighs the banks' previous discretion in shaping contractual provisions.

For the borrower, this means that every annex signed before the publication of the opinion or in its immediate vicinity may be assessed through the prism of EU protection standards. If the document contains unfair terms that case law explicitly challenges, the chance of challenging the installment amount becomes real. Banks no longer have room for free interpretation of the law, and any attempt to impose unfavorable conditions in a hurry may be considered an act inconsistent with consumer law.

The dispute over the interpretation of terms imposed on clients has become a legal battle. Banks are trying to maintain their position, arguing that the Advocate General's opinion refers to the future, not to already signed annexes. However, lawyers specializing in Swiss franc and zloty loan cases point out that CJEU case law usually has a retroactive effect in the context of interpreting EU law. This means that people who have already signed annexes may in the future challenge their provisions if it turns out that they were constructed in violation of the principle of transparency and contractual balance.

Historical perspective: From June 2022 to today

The debate over moving away from WIBOR did not arise in a vacuum. As early as June 2022, financial institutions and supervisory bodies pointed to the need to reform reference rates. At that time, WIRD and WIRF were identified as successors that would better reflect the situation in the money market. The promise was clear: installments were to decrease thanks to a more adequate index. For three years, the market lived in uncertainty, and banks tested various mathematical models, waiting for final legal resolutions.

The establishment of WIRF as the official successor to WIBOR on January 30, 2025, was the culmination of these years of work. However, after this decision was announced, the optimism of borrowers collided with the brutal reality of bank annexes. Banks, possessing knowledge of the upcoming changes, began mass-producing documents aimed not so much at making debt costs realistic, but at securing their margins against a potential drop in market rates.

This situation shows how much the narrative has changed over the last few years. In 2022, there was talk of benefits for borrowers. In 2025, the discussion shifted toward legal protections for banks against the effects of CJEU rulings. Borrowers have become a party in a game where the stakes are not just the amount of the monthly installment, but also the right to fair treatment in relations with a financial institution. What was supposed to be a technological upgrade for the sector has become a battlefield for social justice.

Instructions: How to protect your interests when changing the index?

The borrower's actions should be based on cool calculation, not on fear of deadlines set by banks. The first step is a thorough reading of the documentation. If a bank sends an annex, pay attention to every provision regarding the margin. If the phrase "waiver of claims" appears in the document, it is a warning sign. Consultation with an independent lawyer or financial ombudsman is essential in such a case.

The second step is to verify the method of calculating the new margin. The client has the right to ask the bank for a mathematical justification for the margin change. Does it result from objective costs, or is it an attempt to shift the transformation risk onto the borrower? Financial institutions have an obligation to explain the construction of new provisions. If the bank's response is unclear or evasive, demand a written clarification.

The third step is monitoring case law. The CJEU opinion of September 11, 2025, is publicly available. It is worth checking whether the provisions in the annex you received are consistent with the case law line. Many law firms today offer free or low-cost analyses of annexes for unfair terms. Do not sign documents in a hurry. Even if the bank suggests that not signing will affect loan servicing, stay calm. The banking system is too extensive for a single delay in signing an annex to result in the termination of a loan agreement.

The role of WIRF in the future housing finance model

WIRF, or Warsaw Interest Rate Factor, is an index based on actual transactions in the deposit market. Unlike WIBOR, which was based on bank quotes, WIRF is intended to be more resistant to manipulation and better reflect the liquidity situation. Theoretically, this is a more favorable solution for the client, because rates based on actual transactions are less susceptible to sudden jumps resulting from market emotions.

Nevertheless, the construction of the index itself is only half the battle. The real challenge lies in how banks will use WIRF in their relationship with the client. If this index proves to be exceptionally stable, banks may try to increase margins to maintain the desired level of profitability of their mortgage portfolio. From the borrower's point of view, the stability of the index is valuable, but it cannot be bought at the cost of higher fixed costs in the form of an increased margin.

It is worth noting that WIRF is a solution that fits into European standards for debt valuation. The transition to this model is inevitable and results from EU regulations regarding reference indices. However, the way these regulations are implemented in Poland leaves much to be desired in terms of transparency. Clients are often treated as a passive element of the system that is supposed to accept new conditions without asking questions.

Banking sector: Is the systemic risk real?

The argument about systemic risk, which banks use in the debate about WIBOR, is often abused. Of course, a sudden change in the business model affects the financial results of banks. However, the Polish banking sector has shown record profits in recent years, which undermines the thesis of a threat to stability. Shifting the costs of transformation onto clients is a business decision, not a necessity resulting from the threat of bankruptcy.

Banks fear that a forced change in the interest rate basis will open the door to another wave of legal disputes. They remember the experiences with foreign currency loans, where thousands of lawsuits led to billions in losses for the sector. That is why they are so aggressively pushing for the signing of annexes with waiver of claims clauses. They want to close the path to the courts before borrowers realize that changes in contracts may be the basis for claims for overpaid interest.

For the citizen, this means that banks are operating in defensive mode. It is not about the loan being cheaper, but about it being safe for the bank. A borrower who understands this dynamic will better navigate the negotiation process. Understanding that the bank is not a partner, but a party in a dispute over the margin, allows for more informed decision-making about signing any documents.

Calendar of changes: Schedule until December 2027

The process of phasing out WIBOR has been spread over years. Key dates are not just the moments of index announcements, but above all the deadlines by which banks plan to complete the migration of their portfolios. By December 2027, every loan agreement based on the old index must be updated or terminated. This gives banks time to pursue a long-term strategy of convincing clients to sign annexes.

For the borrower, the most important stages are those in which legal opinions (like the one from September 11, 2025) change the balance of power. Each passing year brings new guidelines that may be more favorable to consumers. Therefore, a "wait and check" strategy is often more effective than haste. If an annex is not necessary for the functioning of the loan at a given moment, it is worth holding off on the decision until all legal issues regarding margins and waiver of claims clauses are clarified.

The time until the end of 2027 is a period for checking whether banks are actually striving for transparency or merely for securing their own profits. During this time, it is worth monitoring the announcements of the Office of Competition and Consumer Protection (UOKiK), which is increasingly speaking out about unfair banking practices when annexing contracts. UOKiK may in the future issue binding recommendations that will force banks to change the content of annexes to be more client-friendly.

Summary of the borrower's situation

Changing the WIBOR index to WIRF is not just a technical operation. It is a profound change in the way loan costs are calculated, which requires the borrower's engagement and knowledge. The most important conclusion from recent years is the need to remain vigilant. Banks, striving to protect their interests, will try to use the transformation process to raise margins, which may negate any benefits resulting from a lower index.

The final installment amount depends on the precise provisions of the annexes signed from 2025 onwards and the CJEU guidelines. Instead of trusting bank assurances about an "essential change," it is better to analyze the documents for legal risks. Calmness and verification of provisions are the best strategy in a world where banks have a huge margin of maneuver in shaping interest rates. Remember that every signed document is binding, and the path to challenging it in court is long and expensive.

Questions and answers

Do I have to sign the annex that the bank sent me?

There is no obligation to sign the annex in a hurry. It is worth consulting the content of the document with a lawyer, as experts point to risks associated with hidden provisions about waiving claims or unfavorable margin adjustments, which is especially important in the context of annexes signed from 2025.

When will WIBOR completely disappear from my loan?

The process of phasing out WIBOR is to be completed by December 2027. By then, all loan agreements must be adapted to the new standard, although banks are already conducting aggressive campaigns urging earlier migration.

Will the new WIRF index be cheaper for my portfolio?

Theoretically, WIRF is intended to make debt costs more realistic by basing them on actual transactions, which may lead to lower installments. However, the real impact on the portfolio depends on the bank's margin. If the bank raises the margin when changing the index, the total cost may remain unchanged or even increase.

What risk does signing an annex with a waiver of claims clause carry?

Signing such a clause may permanently prevent you from pursuing claims in the future, even if case law (including the CJEU guidelines of September 11, 2025) confirms that the method of calculating the margin was unfair. This is the main trap that independent financial advisors and lawyers warn against.

Sources

Article prepared by the Wiadomości PRO editorial team with the support of artificial intelligence. Facts come from the sources listed above.