TreuundGlaubenGrundsatz

Treu und Glauben Grundsatz, often referred to as der Treu und Glauben, is a central general principle in German civil and contract law. It requires parties and authorities to act with honesty, fairness, and reliability in the exercise and performance of rights and duties. The concept operates as a standard for behavior and for interpreting legal relationships, aiming to prevent opportunistic or abusive conduct.

Legal basis and scope: The principle is codified and applied through German law, most notably in the general clause of the Civil Code (BGB § 242). The provision obliges parties to render performance in a manner that is consistent with good faith and customary business practice (Verkehrssitte). Beyond performance, the principle informs contract interpretation, the duty to disclosure and cooperation, and the mitigation of damages. It also constrains how rights may be exercised to prevent unfair results.

Applications: In contract law, Treu und Glauben influences how terms are interpreted, how obligations are fulfilled, and how surprises or loopholes are avoided. It supports duties such as timely information sharing, honest negotiation, and reasonable adjustments to changed circumstances. In employment, lease, or consumer law, it serves as a check against unfair advantage and abuse of rights. Public authorities also apply it to ensure legitimate, non-arbitrary administrative action.

Limitations and relation to other concepts: The principle is not absolute; it balances with other legal rights and demands of fairness, proportionality, and legal certainty. It interacts with related notions of good faith, trust, and fair dealing and has parallels in other civil-law jurisdictions and EU contract practice.