Which Indices Are Currently in Effect?
In May 2025, the WIBOR 3M rate dropped to 5.25%, and the 6M rate to 5.0% – which is why many borrowers are already experiencing lower installments. WIRON still hovers around 5.0 – 5.3%, but updates slower because it “looks back” at deposit transactions.
Key Differences: WIRON vs. WIBOR
- Calculation Method – WIBOR is based on bank forecasts, while WIRON is based on real overnight transactions.
- Reaction Time – WIBOR discounts rate cuts faster; WIRON reacts with a delay of up to 3 months.
- Bank Margin – New mortgages based on WIRON often have higher margins to compensate for the lower base rate.
Will Your Loan Be Automatically Converted?
The government has abandoned the mandatory replacement of WIBOR, but banks may offer addenda. You can get a free profitability analysis with a Wro Finanse advisor. We will check the correcting spread and the new margin before you sign the index change.
Practical Steps for Borrowers
- Monitor the Schedule – The bank is obliged to inform you in advance about any proposed changes.
- Compare the APR Before and After the Change – The total cost matters, not just the rate itself.
- Consider Refinancing – If another bank offers WIBOR or a fixed rate with a lower margin, changing might be cheaper than converting.
Unsure which option to choose? Schedule a free analysis with Wro Finanse – we will show you simulations of WIBOR, WIRON, and fixed rates from several banks and help you choose the most favorable scenario.
