Negative Zinsen sind auch nur 0% Zinsen
An unforeseen negative interest rate in the loan agreement does not generally lead to the lender being obliged to pay
(Judgement Federal Court of Justice (BGH) of 09.05.2023 - XI ZR 544/21)
What the judges say: If the lender and borrower agree on an interest rate depending on a reference interest rate, this does not lead to a reduction in the repayment claim of the loan amount granted according to the basic idea of Section 488 I BGB in case the interest rate becomes mathematically negative. This is because "interest in the legal sense means the remuneration to be paid for the possibility of using temporarily provided capital, which is calculated depending on time but at the same time independent of profit and turnover. [...] According to this definition, interest - because it is a remuneration - cannot become negative." If the interest goes negative, only the lender's interest claim expires. Lenders should therefore be aware of deviating definitions of interest in loan agreements in future, as individual contracts are able to derogate from this definition of the Federal Court of Justice (BGH).