In Polish: Bufor stopy procentowej
This is the word you will see in bank documents.
Definition
The interest rate buffer is the extra percentage points the bank adds to the loan's interest rate when assessing creditworthiness, to check whether you can cope with a higher instalment. For variable rates the supervisor expects a buffer of at least 2.5 percentage points, in line with the 2023 position of the KNF Office (UKNF). For rates fixed for at least 5 years, some banks apply a lower buffer or calculate creditworthiness at the fixed rate alone.
What it means for you
The buffer does not change the instalment you pay, but it lowers the amount the bank can lend you, by roughly one fifth. If your creditworthiness falls short, a fixed rate at a bank that calculates it without the full buffer can give a noticeably higher amount. Remember, though, that after the fixed period the instalment may rise.
Full entry in Polish, with a worked example and sources
Frequently asked questions
What is the KNF buffer for a mortgage?
For a variable rate, at least 2.5 percentage points above the offered rate, in line with the UKNF position. With an offer at 6.5%, the bank calculates the instalment at 9%.
Does the bank add a buffer with a fixed rate?
It depends on the bank. With a rate fixed for at least 5 years, some banks calculate creditworthiness with a lower buffer or at the fixed rate alone, which gives a higher loan amount.
Does the buffer raise my instalment?
No. The buffer is only used to calculate creditworthiness. You pay the instalment at the rate in your agreement.
Related terms
Definitions are simplified and reflect Polish law and bank practice as of October 2026. Where every word matters, the Act and your loan agreement decide. Figures in examples are indicative and are not a bank offer. The Polish version of each entry has worked examples and sources.
Other terms in “Creditworthiness and down payment”