WIBOR Phase-Out Hits Millions of Polish Borrowers as POLSTR Switch Looms

Millions of Polish bank customers face critical contract amendments as the benchmark interest rate WIBOR is replaced by POLSTR, raising legal concerns over future claims.

What Is WIBOR and How Does It Affect Loan Installments?

WIBOR determines the interest rate on the Polish interbank market, serving as the rate at which banks borrow from each other. Alongside the bank’s margin, this variable rate directly impacts the monthly installment amounts paid by borrowers.

Depending on macroeconomic conditions, rising interest rates push WIBOR higher, leading to increased loan installments for consumers.

WIBOR Departs, POLSTR Arrives

WIBOR is set to be replaced by the POLSTR index, with the change taking effect for new contracts from January 1, 2027. For existing agreements, WIBOR may remain in use until 2036, though transitioning earlier requires signing an annex to the loan agreement.

Advocate Jakub Bartosiak from MBM Legal warns that signing the annex could extend beyond a mere technical update, potentially leading courts to treat the document as a confirmation of original terms, acceptance of past practices, or a waiver of future claims against the bank.

Borrowers Should Demand Time to Analyze Documents

Bartosiak advises that consumers should demand the removal of any clauses waiving original claims and avoid confirming the validity of the original agreement or past interest-rate calculations before signing.

While proper bank communication should allow clients time to consult lawyers, experts note that banks may use these amendments to regulate additional fees, spreads, or past practices.

Refusing the Annex Will Not Invalidate the Contract

According to current draft legislation highlighted by Dr. Wanesa Choptiany-Mańka from WSB Merito University, borrowers who refuse or fail to respond to the annex will not lose contract protection, nor can banks use refusal to terminate loans or raise margins.

Legal experts emphasize that because the legislation is still a draft, borrowers should carefully evaluate whether the proposed document impacts rights beyond the mere benchmark transition.

Negotiation Prospects and Legal Consequences

Given the mass rollout, banks are expected to use uniform templates with limited room for individual negotiations, though clients still retain the right to question terms and document refusals.

Ultimately, while signing the annex does not automatically strip borrowers of their rights, courts may consider the signed text during legal disputes against the bank.