The most important formal legal source of contract law is the Obligations Code (hereinafter OZ).28 This code comprehensively regulates obligations, and its provisions generally apply to all types of contracts. The OZ consists of two main parts: the first, general part contains the general rules of the law of obligations, while the second (special) part covers specific contracts.29 The rules of the general part apply to all obligations, whereas the rules of the special part regulate specific types of contractual relationships. The legal rules contained in the provisions of the OZ have the nature of general rules (lex generalis) within the hierarchy of the law of obligations. Their application can therefore be excluded (derogated) either by more specific rules or by newer general rules.
The field of contract law is also significantly supplemented by other laws. Consumer law, primarily regulated by the Consumer Protection Act (ZVPot-1)30 and the Consumer Credit Act (ZPotK-2)31 as well as various other regulations, governs certain obligations and contractual relationships differently from general obligations law, predominantly in favour of the consumer (in favorem consumatoris). This represents a specific regulation of obligations or contractual relationships based on the parties involved (consumers).32 Property relations between spouses, particularly the conclusion of legal transactions between them, are governed by the Family Code (DZ).33 The field of obligations law is further regulated by numerous other laws, particularly those concerning the prevention of unfair business practices, lease relationships, transport law, securities and other financial instruments, intellectual property, and more.34
In contractual obligations involving business entities, business customs, practices, and established dealings between the parties are also considered when assessing the necessary actions and their effects.35 It is important to note that the general clause on the application of business customs, practices, and established dealings is intended for business entities, although this does not mean it applies exclusively to contractual relationships between such entities. The rules of customs, practices, and established dealings between parties also apply in general obligations relationships, but only when a specific legal rule explicitly refers to one of these standards.36 The concept of a business entity is broader than that of a commercial company and is interpreted in accordance with Article 13 of the OZ, which is discussed in detail in Chapter 5.
A business custom refers to certain conduct expected among persons with specific characteristics, particularly business entities. Its defining elements are the definiteness of conduct, the expectation of such conduct, and the qualification of the subjects to whom it applies.37
Practices are detailed rules within a specific narrower business circle, most often adopted by associations of business entities (such as chambers of commerce) or individual business entities (like stock exchanges or banks), rather than by the legislature.38 Example: Practices include the Special Construction Practices, which are used to assess construction contracts.
Established dealings between parties refer to a practice that exists when parties have maintained continuous business relations over a certain period. In addition to ongoing business cooperation, it is necessary to consider the repetition of similar transactions with similar content in previous contractual relationships.39
An important informal legal source is also established case law. When making decisions, courts must not arbitrarily deviate from consistent and established case law without reasonable legal justification.40 Case law is presented at https://www.sodnapraksa.si/.
Exercise:
In accordance with Article 540 of the Obligations Code (OZ), a donor may revoke a gift contract due to gross ingratitude if, after its conclusion, the donee behaves towards the donor or their close relatives in a manner that, according to fundamental moral principles, would make it unjust for the donee to retain the received gift.
In the case law of the higher courts and the Supreme Court of the Republic of Slovenia, find three examples where the court ruled that the specific factual circumstances met the standard of gross ingratitude. Cite the decisions with the case reference number, date of issue, and the name of the court.
