Radical Changes Ahead for Millions of Polish Borrowers as WIBOR is Replaced by POLSTR

Millions of bank borrowers in Poland face significant contract amendments as the WIBOR interest rate benchmark is phased out in favor of POLSTR, sparking legal warnings regarding future claims.

What is WIBOR and how does it affect loan installments?

WIBOR is an indicator determining the interest rate on the Polish interbank market, representing the interest rate at which banks lend money to each other. It is variable, and its level—alongside the bank’s margin—directly affects the amount of loan installments.

It is WIBOR that determines whether borrowers pay higher or lower installments. When the indicator rises along with interest rates, installments also go up, depending on the broader macroeconomic context of the Polish economy.

WIBOR departs, POLSTR arrives

A major change is coming as WIBOR will be replaced by the POLSTR indicator. For new contracts, the change is scheduled to take effect on January 1, 2027, while in already concluded contracts, WIBOR may function until 2036, with earlier transition requiring a contract annex.

According to attorney Jakub Bartosiak from MBM Legal, cited by MondayNews, the significance of the annex may extend beyond the mere change of the indicator, potentially affecting future disputes with banks or leading to the waiver of certain claims.

Bartosiak explains that before signing the document, consumers should demand the removal of any waivers of claims regarding the original contract and avoid confirming that they understood all interest-rate determination principles at the initial date of signing.

Borrowers should analyze documents carefully

Jakub Bartosiak notes that the annex’s meaning will depend on how banks inform clients about the proposed change, ensuring borrowers have adequate time to review the document and consult a lawyer.

The lawyer does not expect anyone to make such a decision with full awareness of its consequences without potential compensation or benefits offered to borrowers.

The change from WIBOR to POLSTR may not be purely technical

Dr. Wanesa Choptiany-Mańka from WSB Merito University points out that while the replacement is often described as technical, its assessment for consumers depends entirely on the exact contents of the proposed annexes.

Attorney Jakub Bartosiak comments that since an annex requires a new agreement between the bank and the borrower, there is no obligation to sign it.

Lack of signature will not be grounds for contract termination

Dr. Choptiany-Mańka highlights that under the current draft bill, a borrower who refuses to sign the annex or does not respond will not lose contract protection, and refusal cannot form the basis for contract termination or raising margins.

Legal counsel Jarosław Chałas from Chałas and Partners emphasizes that borrowers should avoid making automatic decisions under time pressure and first determine the legal consequences of the proposed document.

Annexes may include additional provisions

Dr. Choptiany-Mańka warns that banks might use the annex to regulate other issues related to loan execution, such as additional fees or spread changes.

Legal counsel Jarosław Chałas adds that borrowers must verify whether the annex contains statements confirming the bank’s proper performance, waivers of claims, or debt amount recognitions.

While signing an annex does not automatically deprive a borrower of the right to pursue claims regarding an initially invalid contract, banks may use the signed document as a procedural argument in court.

Jarosław Chałas explains that the legal weight of the annex will depend on its specific content and whether it includes statements exceeding a purely technical benchmark change.

Will borrowers be able to negotiate the annex?

Dr. Choptiany-Mańka observes that given the large number of active contracts, banks are likely to prepare uniform template documents, leaving individual clients with limited room for negotiation.

Nonetheless, experts advise that the mass nature of the process does not exempt banks from legal obligations, and borrowers should still review, question, and document any refusals from banks.