When concluding bilateral contracts, participants adhere to the principle of equal value of reciprocal performances.57 The OZ specifies the cases in which a violation of this principle has legal consequences.58 Contracting parties must ensure that the value of what they give and receive is equivalent (if one party pays a certain price, the other party must provide goods or services corresponding to that price). It is important to emphasise that this principle does not have absolute validity, as it applies only to bilateral contracts, and not all of them, while a violation of this principle has legal consequences only when prescribed by law.59
Example: If a buyer pays €1,000 for a certain product, that product must be worth €1,000. – If the product is not worth this price (e.g., it is damaged or of poor quality), the principle of equal value of performances is violated.
A landlord and a tenant conclude a contract under which the tenant pays a monthly rent. In return, the landlord must provide suitable housing. – If the housing is inadequate (e.g., there is no heating or there are serious roof issues), the principle of equal value of performances is not respected.
