Introduction

The global labor market is undergoing a fundamental transformation. Traditional employment models—based on permanent, full-time contracts—are increasingly giving way to new and more flexible forms of working relationships. This shift constitutes one of the defining characteristics of the 21st-century economy. Factors such as economic globalization, advances in communication technologies, the rise of the gig economy, and businesses’ increasing need to reduce fixed costs have all accelerated this transition. At the center of these changes are flexible work contracts, which enable employers to adjust their workforce in response to fluctuations in market demand. Among these emerging models, zero-hour contracts (ZHCs) have emerged as one of the most flexible—and most controversial—forms of employment relationships.
Originating primarily in the common law system—particularly in the United Kingdom—ZHCs create an employment relationship in which the employer has no obligation to provide a minimum number of working hours. Conversely, in non‑exclusive arrangements, the worker is not required to accept the work offered. Payment is made solely for the hours actually worked. While this structure obviously responds to the needs of sectors such as services and retail, it can create a significant lack of job and income security for workers.
The Iranian legal system lacks statutory provisions or a specific legal definition, yet signs of similar arrangements are emerging in online platforms and seasonal businesses in the country. This practical reality presents the legal system with a serious legislative vacuum. The central issue lies in the apparent tension between ZHCs and the fundamental rules governing the validity of transactions in Imāmī jurisprudence (fiqḥ), as well as the protective principles of the Iranian Labor Law.
The present study tried to address the following research questions: What is the legal status of ZHCs in the Iranian legal system, given their apparent conflict with the rule of gharar in Islamic jurisprudence and the protective principles of the Iranian Labor Law? Furthermore, can a legal mechanism be developed to validate these contracts conditionally without undermining the fundamental rights of workers?

Literature Review

The topic of ZHCs has received limited attention in Iranian legal scholarship. Existing research can generally be divided into three categories. The first category includes studies on the general principles of contracts in Islamic jurisprudence and civil law. The second category consists of labor law research focusing on definite and indefinite employment contracts. Although scholars have examined job security in temporary contracts and the judicial precedent of the Court of Administrative Justice, they have not specifically addressed the floating or indeterminate nature of working hours in ZHCs. The third category encompasses general studies on the gig economy. While these works discuss flexible work arrangements more broadly, they lack a detailed jurisprudential and legal analysis of the validity of ZHCs in Iran.

Materials and Methods

This research adopted a descriptive–analytical approach based on library research. The primary sources included authoritative works of Islamic jurisprudence, Iran’s statutory laws (particularly the Civil Code and Labor Law), legal doctrine, and the experience of selected legal systems, such as those of the United Kingdom and New Zealand. The analysis began by examining the nature and characteristics of ZHCs from a comparative perspective. It then applied the analytical tools of legal reasoning and Imāmī jurisprudence to assess the validity of ZHCs. The focus was on resolving the tension between the need for flexibility and the peremptory rules of Iranian law.

Results and Discussion

ZHCs are distinct from similar arrangements (e.g., hourly employment contracts, piecework, and reward contracts or juʿālah) recognized under Iranian law. Their defining feature is the combination of employment subordination—which brings them within the scope of the Iranian Labor Law—with the absence of any mutual obligation to offer or accept a minimum amount of work. Unlike standard hourly contracts, under which a basic framework of working hours is usually agreed upon, ZHCs contain no guaranteed minimum of work.
From the perspective of Imāmī jurisprudence, the principal obstacle to the validity of ZHCs is the rule prohibiting excessive uncertainty or risk known as the rule of gharar. Because the employer does not guarantee a minimum number of working hours, both the subject matter of the contract (the quantity of work) and the consideration (the total wages) remain indeterminate at the time the agreement is concluded. This research argues that although the degree of gharar at the outset appears significant, the contract may still be validated under the principle of validity (aṣālat al‑ṣiḥḥa) if certain legal mechanisms are incorporated. In particular, the study suggests that the element of uncertainty can be mitigated either by transforming it into a reasonable and customary commercial risk or by introducing appropriate contractual stipulations that clarify the parties’ rights and obligations.
Under the Iranian Labor Law, ZHCs appear to conflict with Article 7, which requires a definite subject matter for employment contracts, and Article 36, which relates to social security contributions. The absence of guaranteed working hours undermines the principles of job security and economic security that underpin labor protections. Moreover, the current social security system in Iran is structured around continuous employment. As a result, the sporadic and irregular working hours characteristic of ZHCs may create gaps in workers’ insurance records, potentially depriving them of retirement and medical benefits.
The current study evaluated two approaches to obviate the challenge. The first is the approach advocating for employer restriction. This approach proves to be inefficient in the Iranian context, as it undermines the flexibility required by production sectors and may push employment into the informal or black market. Instead, the study proposed a second, more innovative approach: worker empowerment and social security modernization. This model is built on three pillars as elaborated below.
The first pillar is statutory non-exclusivity. The law must explicitly prohibit exclusivity clauses in ZHCs. Worker security should not come from forcing a single employer to pay for idle time, but from allowing workers to hold multiple ZHCs simultaneously. The second pillar is the modernization of the social security system through the adoption of an hourly-based model. The social security system should be reformed so that insurance premiums are calculated and collected based on actual hours worked rather than on a daily or monthly basis. This would ensure that, even in fragmented employment, workers continue to build uninterrupted social security records. The third pillar is the establishment of a supplementary hourly unemployment fund. A specific mechanism should be established under which a small percentage of each hourly wage is deposited into a supplementary unemployment fund to support workers during periods of low demand.

Conclusion

The emergence of ZHCs places the Iranian legal system at a crossroads between traditional protectionism and modern economic realities. This research concludes that ZHCs, in their absolute and unregulated form, are invalid because they conflict with the jurisprudential rule of gharar and the protective principles of the Iranian Labor Law. However, declaring them entirely void is not a viable solution, as it disregards the realities of the labor market.
The analysis showed that attempting to force ZHCs into traditional molds—such as by imposing mandatory minimum hours—is counterproductive. The optimal solution lies in systemic reform based on a flexible security approach. By legally prohibiting exclusivity clauses and modernizing the social security system to support cumulative, hourly‑based benefits, the legal system can allow these contracts under regulated conditions. Such an approach preserves the flexibility needed for economic growth while protecting workers’ fundamental rights and livelihoods.