Ⅰ. INTRODUCTION
Contracts are legal transactions established on the basis of the parties' intentions. Particularly in commercial relations, the need to conclude contracts swiftly and adapt them to operational requirements may occasionally lead to certain provisions remaining incomplete or uncertain. The absence of explicit determination regarding the content, duration, consideration, or conditions of performance in a contract is a situation frequently encountered in practice.
In such cases of uncertainty, declaring the contract entirely void would not be practically equitable; therefore, the courts assume a supplementary role by determining the missing provision. This article examines the scope of the courts' authority to determine performance provisions, its relationship with the principle of freedom of contract, and the practical issues arising in its application.
ⅠⅠ. UNCERTAINTY OF PERFORMANCE PROVISIONS IN CONTRACTS
Performance is one of the essential elements of a contract. Pursuant to Article 1 of the Turkish Code of Obligations No. 6098 ("TCO"), a contract is established by the mutual and corresponding declarations of intent of the parties. However, in practice—particularly in framework agreements, preliminary protocols, or standard contract forms—issues concerning performance are not always set out clearly and in detail:
- The delivery period may only be expressed as "within a reasonable time,"
- The price may be left as "to be agreed upon by the parties at a later stage,"
- The scope of the service is often left unspecified.
In such cases, whether a contract has been formed and, if so, whether it is enforceable becomes a matter of debate. Especially in commercial disputes, the Court of Cassation tends to recognize the contract as valid rather than declaring it invalid. Indeed, as can be seen in the decision of the General Assembly of the Court of Cassation dated 07.06.2022, with file number 2019/717 and decision number 2022/848:
"On the other hand, if the judge determines, upon examination, that the parties do not have a mutual contractual intent, there may be a gap in the contract, and if the conditions are met, this gap may be filled through the supplementation of the contract."
thus, courts ensure the performance of the contract by filling in the missing elements. In this way, the functionality of the contract in commercial life and the legal certainty between the parties are preserved.
At this point, the legal basis of the court's supplementary role becomes crucial. According to Article 2 TCO, the principle of good faith governs the interpretation of contracts, whereas Article 27 TCO provides that general invalidity occurs only if the subject matter of the contract is impossible or contrary to morality or public policy. Therefore, the mere existence of a gap in the contract does not automatically render it void. Under Article 16 TCO, the essential elements of a contract must be definite or determinable for it to be legally effective. Furthermore, pursuant to Articles 26–27 TCO, matters not expressly regulated by the parties are supplemented by dispositive legal provisions. Accordingly, rather than declaring the contract invalid, the court may rely on supplementary legal rules, commercial customs, the principle of good faith, and the parties' previous course of dealings to determine the uncertain performance provision. This approach enables the preservation of the parties' intentions and the continuation of the contract's validity.
III. THE SCOPE AND LIMITS OF THE COURT'S SUPPLEMENTARY ROLE
In cases where the performance, which is one of the essential elements of contracts, is left undefined, courts assume a supplementary role to make the performance of the contract possible. Similarly, in cases where the delivery time is regulated in the contract with vague expressions such as "to be agreed upon by the parties," the principle of performance within a reasonable time under Article 90 of the Turkish Code of Obligations (TCO) comes into play, and the concept of "reasonable time" is mostly interpreted in line with commercial customs. For instance, as can be seen in the decision of the 15th Civil Chamber of the Court of Cassation dated 21.11.2019, with file number 2019/2210 and decision number 2019/4750:
"There is no written contract between the parties, nor is there an agreement on the price of the work. Therefore, the price of the work should be calculated according to the local market prices of the year in which the work was carried out, pursuant to Article 481 of the TCO, as also adopted in the practices of the Court of Cassation. The court should obtain the relevant project documents and, in accordance with Article 281/2 of the Civil Procedure Code (HMK), request an additional expert report to calculate the price of the work (including VAT) based on market prices at the time the work was performed, deducting any payments acknowledged or proven by the claimant, and render a decision accordingly."
In consultancy or architectural contracts where the scope of the service is not clearly defined, courts resort to technical experts to concretize the subject of the contract and enable performance. However, the addition of provisions to the contract by the court brings forth a significant debate in both doctrine and practice. According to the principle of freedom of contract, the court cannot replace the will of the parties; however, in terms of legal certainty and security of commercial transactions, it may be necessary for the court to complete certain missing provisions where the parties have clearly expressed their intent but have left some terms incomplete. At this point, the court should not create a new regulation on which the parties have not explicitly agreed but should only resolve the ambiguity in a manner consistent with the parties' intent.
That said, this authority of the courts must be exercised with caution. Otherwise, the judiciary risks evolving into an authority that applies its own judgment rather than respecting the will of the parties. Such an approach would undermine the principle of freedom of contract and could expose the parties to outcomes inconsistent with their pre-agreed expectations. Therefore, the court's supplementary role should be confined to contracts in which essential terms are left uncertain, but the parties' declarations of intent are otherwise clear; and the intervention must align with the parties' reasonable expectations.
Ⅳ. PRACTICAL CONSEQUENCES OF UNCERTAIN PERFORMANCE PROVISIONS IN COMMERCIAL LIFE
The uncertainty of performance provisions in commercial contracts is significant not only from a legal perspective but also due to the practical consequences it generates. Such uncertainty often gives rise to disputes during the performance stage, disrupting commercial relationships and causing additional costs. In this respect, the courts' supplementary role not only preserves the validity of the contract but also serves the broader objectives of commercial stability and security.
For example, in contracts where the delivery period or the scope of services is left vague, judicial determination can balance the parties' expectations and prevent prolonged disputes. Similarly, the absence of an agreed price may otherwise allow one party to exploit its bargaining power; however, when the court determines the consideration based on objective criteria, such imbalances can be eliminated.
Thus, the judicial determination of uncertain performance provisions is not merely a matter of "filling a legal gap"; it also functions as a tool for sustaining business relationships. This approach ensures that contracts remain functional in line with the dynamics of commercial life, while simultaneously reinforcing mutual trust between the parties.
Ⅴ. CONCLUSION
In conclusion, where an essential element of a contract such as performance is left uncertain, the courts' supplementary role arises as a necessity derived both from the provisions of the Turkish Code of Obligations and from the fundamental principles of contract law. Pursuant to Articles 16, 26, and 27 TCO, the determinability of essential terms is sufficient for a contract's validity, while any omissions are remedied through supplementary legal rules, commercial customs, and the principle of good faith. This approach ensures that the essence of the freedom of contract is not undermined, while simultaneously preserving the parties' intentions and upholding the contract's functionality.
Nevertheless, judicial intervention cannot be construed as an unlimited power. The creation of a provision by the court where the parties have expressed no intent at all would constitute a direct violation of the principle of freedom of contract. Accordingly, the role of the courts is not to substitute the parties' will, but rather to interpret existing declarations of intent in a supplementary manner.
It must also be acknowledged that uncertain performance provisions may, at times, reflect the parties' deliberate strategic choice. From this perspective, judicial intervention does more than simply fill in omissions; it also balances the parties' commercial strategies, ensuring that the contract is sustained in a fair and equitable manner. This protects mutual trust between the parties and fosters predictability and stability in commercial transactions.
Ultimately, in the ever-changing dynamics of commercial life, the emergence of uncertain provisions is inevitable. In such circumstances, the role of the courts is not to terminate contracts but to safeguard the parties' intentions and enable the continuation of contractual relations. This approach responds to the needs of economic life while offering a solution consistent with the fundamental principles of contract law.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
