New Ruling by the Federal Court of Justice on the Reference Interest Rate for Interest Adjustments in Bonus Savings Contracts
On December 9, 2025, the Federal Court of Justice (BGH) once again dealt with the issue of interest adjustment clauses in long-term bonus savings contracts. The decision was issued in cases XI ZR 64/24 and XI ZR 65/24 (source: urteile.news). The focus was on the question of which reference interest rate must be applied for interest adjustments and how the adjustment mechanisms must be structured in relation to consumers.
Background of Interest Rate Adjustments in Bonus Savings Contracts
Development of Case Law
In the past, the BGH had already addressed clauses on interest rate adjustments in savings contracts several times. Key issues included the transparency of the clauses as well as the standard to be applied to implement interest changes during the contract term. In particular, the effects of long-term low interest rate phases and their compensation in existing contracts were a focal point.
Significance for Consumer Contracts
Bonus savings contracts were often concluded with variable interest adjustment provisions. As a result, banks unilaterally adjusted the interest on savings balances using internal company algorithms or based on market-observed reference interest rates. In the past, many consumers believed that the clauses used by the credit institutions did not sufficiently reflect adverse interest developments to the detriment of savers.
Key Points of the Current BGH Decision
Determination of the Relevant Reference Interest Rate
In its current ruling, the BGH clarified which reference interest rate is decisive for calculating variable interest adjustments in bonus savings contracts. The question was whether the relevant rate must be derived from certain publicly available interest rates or from specific reference values defined by banks. In doing so, the court relied on principles developed in earlier decisions.
Requirements for the Calculation Method
Another focal point was the requirements for the specific calculation method. The BGH reinforced that the adjustment of the contractual interest rate to the reference interest rate must be made at reasonable discretion and that both time periods and the smoothing of interest rate developments must be taken into account. In addition, consumer protection aspects as well as the appropriateness and transparency of the interest adjustment methods must be considered.
Consequences of the Decision for the Contracting Parties
Impact on Ongoing Contracts
The court’s reasoning once again provides guidance to the lower courts on how to proceed in disputes concerning incorrect interest adjustments in existing bonus savings contracts. In case of doubt, credit institutions must demonstrate that the adjustments were based on an appropriate and transparent reference interest rate. Furthermore, in pending proceedings, the final clarification of the circumstances of the individual case may be subject to further judicial review.
Significance for Contract Design
In light of the current BGH case law, there remains a future need to structure interest adjustment clauses in new bonus savings contracts according to clearly defined standards and in compliance with the transparency requirement. The decision therefore increases legal certainty for both credit institutions and investors and savers when dealing with variable interest rates.
Concluding Remark
The ongoing legal development concerning interest adjustments in long-term savings contracts regularly presents market participants and credit institutions with complex issues. In particular, new challenges arise continuously in relation to the reference interest rate and transparency requirements. In case of uncertainty regarding existing contractual relationships or planned arrangements, personalized legal evaluation tailored to the individual situation is recommended. If you have legal questions in the area of banking law, you are welcome to contact us for a non-binding consultation via Legal Advice in Banking Law.
