A. Introduction Suretyship contracts in Turkish law were previously regulated under Articles 483 and subsequent provisions of the repealed Code of Obligations (eCOO). Under the current Turkish Code of Obligations (TCO), they are addressed in Articles 581 and subsequent provisions. Article 581 of the TCO defines a suretyship contract as follows: “A suretyship contract is an agreement in which the surety assumes personal liability to the creditor for the consequences of the principal debtor’s failure to fulfill their obligation.”
As stipulated in the provision, the surety assumes the risk of the principal debtor’s failure to fulfill their obligations, either in part or in whole, and provides personal security to the creditor. Such agreements are typically formed when the trust relationship between the parties is weak or when the creditor seeks additional assurance to secure their receivables. In these agreements, a third party, other than the debtor, provides security to the creditor by assuming the risk of the debtor’s non-performance. Suretyship agreements are thus categorized as personal guarantees. Due to their importance, such contracts are subject to strict formal requirements under the law. To be valid, suretyship contracts must meet the following conditions:
1. Competency Requirements The surety must have full legal capacity to enter into a suretyship agreement. Minors and individuals under guardianship cannot act as sureties. Moreover, the law prohibits guardians from entering into suretyship agreements on behalf of their wards (Turkish Civil Code [TCC] Art. 449). This prohibition also applies to parents acting on behalf of their children under parental authority (TCC Art. 342/3). Since only the surety is bound by the contract, such agreements cannot be executed with the permission of guardianship or supervisory authorities on behalf of the ward.
For legal entities, their capacity is limited by the objectives stated in their founding documents (e.g., association bylaws, foundation charters, articles of incorporation). Legal entities can act as sureties only within the scope of their stated objectives. Furthermore, the provisions on defective intent (fraud, duress, and misrepresentation) under Articles 30-39 of the TCO also apply to suretyship agreements.
2. Existence of a Valid Principal Obligation A suretyship agreement can only be formed for an existing and valid obligation (TCO Art. 582/1). If the principal obligation is invalid due to impossibility, illegality, immorality, lack of form, simulation, or incapacity, the suretyship agreement is also invalid. However, it is not necessary for the principal obligation to exist at the time the suretyship agreement is formed. Suretyship agreements may also be established for future or contingent obligations, becoming effective once the obligation arises or the condition is fulfilled. It suffices that the principal obligation exists at the time the creditor seeks recourse to the surety.
3. Formal Requirements: Written Form, Date, Amount, and Handwritten Provisions The formal requirements for suretyship agreements are set forth in Article 583 of the TCO: “A suretyship contract is invalid unless it is made in writing, specifies the maximum amount for which the surety is liable, and indicates the date of the suretyship. Furthermore, the surety must state in their handwriting the maximum amount they are liable for, the date, and, if applicable, their solidarity as a joint surety.”
This provision establishes enhanced formal requirements for suretyship agreements. Such contracts may be executed in either notarial or simple written form. However, the surety must personally write the maximum liability amount, the date, and, in the case of joint and several liability, an acknowledgment of their solidarity in their handwriting. These requirements are mandatory for the validity of the agreement. Non-compliance renders the contract absolutely null and void, which the court must recognize ex officio, even if not raised by the parties.
If the surety makes payments under an invalid contract without knowing of its invalidity, they may reclaim the payments under unjust enrichment principles. However, if the surety knowingly makes such payments, they are deemed a gift and cannot be recovered.
The same formal requirements apply to promises to act as a surety and transactions executed through representatives. However, there is debate among scholars regarding whether a representative’s document, notarized and explicitly stating the date, maximum liability, and solidarity, requires the surety’s handwritten confirmation of these details.
Any amendments to the suretyship agreement that increase the surety’s liability must also comply with these formal requirements (TCO Art. 583/3).
4. Written Spousal Consent and Exceptions Another statutory requirement is the written consent of the surety’s spouse. According to the law, a married individual must obtain their spouse’s written consent before entering into a suretyship agreement, unless there is a court decree for separation or a statutory right to live separately. This consent must be given before or at the time of the agreement’s execution. Obtaining spousal consent after the agreement is executed does not validate the contract.
If a court grants a divorce or separation decree (TCC Art. 170), the requirement for spousal consent is waived. This requirement is also a validity condition, and failure to comply renders the contract invalid. It is debated in doctrine whether spousal consent is necessary when one spouse acts as a surety for the other’s obligations. Some scholars argue that consent is still required, while others assert it is unnecessary. In my opinion, spousal consent should not be required in such cases.
Additionally, amendments that increase the surety’s liability, convert a simple suretyship into joint and several suretyship, or significantly diminish the surety’s safeguards also require spousal consent (TCO Art. 584/2).
Exceptions to the spousal consent requirement are also stipulated by law. These include suretyships provided by individuals registered in the trade registry for commercial enterprises, partners or managers of companies for company-related matters, artisans for professional activities, guarantees under the Public Banks Interest Support Credit Law (Law No. 5570), and loans extended by agricultural or artisan credit cooperatives or public institutions to cooperative members (TCO Art. 584/3).
