Pacta sunt servanda

Pacta sunt servanda (Latin, German contracts are kept) is the principle of contractual loyalty in public and private law.

This is the main principle of public as well as private contract law. In the German civil law there is the general principle of the obligation to fulfill obligations - and therefore also of contracts - in § 241 paragraph 1 BGB. One of the most important developments of this principle is to be found among others in the event of good faith again, which is regulated in § 242 BGB. The principle says that the person who breaks contracts, acts unlawfully. Furthermore, the principle of contractual fidelity force of international customary law, in which he states in the theory dispute over the question of the binding international treaties that national laws must not be grounds for non-compliance applies.

It closed contracts are in principle also informally (eg, oral) binding.

Only in exceptional cases provides the German law that contracts in a certain form must be closed and are void when not in compliance with these formal requirements. One such exception is for example the land purchase contract, which shall 311b BGB a notarization pursuant to §. Other exceptions to the principle of contractual loyalty can be found at the doorstep § 312, paragraph 1, of distance contracts, § 312 para 1 sentence 1 (consumer protection) and in case of failure of the basis of § 313 BGB (see Withdrawal).


The sentence itself is not derived from Roman law. In Roman law of the classical period (1st to 3rd century AD), namely a binding and thus actionable contract arose only if the consensus of the parties was dressed in one of the approved contracts. The contrast with the enforceable contract ( contractus ) was formless and therefore unklagbare pactum. They could just as part of a pactum adiectum ( ancillary ) - ie a pactum, which was an additional agreement to form a treaty requiring such a stipulatio, closed - and only be asserted in bona fides Suits. The numerus clausus actionable contracts was only gradually extended until the Middle Ages and the canon law developed from religious considerations the principle " pacta sunt servanda ". The first written confirmation is found in the Liber extra of Gregory IX. The principle should express that even informal agreements ( pacta nuda ) are legally binding and not just the CONTRACTUS of Roman law.

The enforceability of all informal promises soon raised new problems, as is business inexperienced contractors seemed less protected against ill-considered business transactions. As a new demarcation criterion for a serious contractual intent, one used the Causa - teaching. The validity of a contract should not be judged on the form, but to the purpose of authorizing an agreement has been concluded.