Supreme Court General Assembly of Civil Chambers, 25.03.2021, E. 2016/2412, K. 2021/343

A termination notice is “a unilateral right that terminates a continuous (fixed-term or indefinite-term) employment contract immediately or upon the expiry of a certain period, and by reaching the opposing party, creates a dissolving effect,” and is “a declaration of will that does not require the consent of the opposing party.” The Board also emphasized that “pursuant to Article 19 of the Labor Law, the termination notice must be in writing and its reason must be clearly and definitively stated.”

Principle derived from the decision: Termination is a unilateral declaration of will that takes effect upon reaching the opposing party and does not require acceptance. However, for termination with a valid reason, a written form and a clear and definite reason are mandatory pursuant to Article 19 of the Labor Law.

How is it used in practice?: When a WhatsApp message reaches the opposing party, the intention to terminate may be considered declared; therefore, instead of deeming the message “invalid” and waiting, the employee should calculate the deadlines accordingly. On the other hand, if the message does not meet the form and content requirements of Article 19, the invalidity of the termination may be asserted.

9th Civil Chamber of the Supreme Court, 20.09.2017, Docket No. 2016/19135, Decision No. 2017/13760

Conclusion: It has been stated that if there is no written notice, the termination should be deemed invalid and re-employment should be ordered.

“The court, by delving into the merits of the case, should first determine whether it is an employer termination, and if it is an employer termination, since no written notice was given, pursuant to Article 19 of the Labor Law No. 4857, a decision should be made regarding the invalidity of the termination and the re-employment of the plaintiff.”

Principle derived from the decision: The court must first determine by whom the termination was made. If it is understood that the termination was made by the employer and no written notification was given, the termination is invalid under Article 19, and the employee’s reinstatement is ordered.

How is it used in practice?: Against the employer’s frequently invoked defense “the employee quit themselves,” the employee must present WhatsApp messages showing the employer’s intent to terminate employment. If the termination is found to be made by the employer and there is no written notification, a reinstatement decision is issued.

Supreme Court 9th Civil Chamber, 01.06.2017, E. 2016/14206, K. 2017/9527

“While fulfilling the burden of proof, the employer will primarily demonstrate compliance with the formal conditions of termination. Accordingly, the termination must have been made in writing, the employer must have documented requesting the employee’s defense in certain situations, and the termination reasons on which it is based must have been shown concretely and clearly within the content of the written termination process.”

Principle derived from the decision: The employer’s burden of proof begins first with formal conditions: (1) is the termination in writing, (2) was a defense requested when necessary, (3) are the termination reasons shown concretely and clearly? The merits of the termination are not examined before these conditions are met.

How is it used in practice?: If an employer cannot document these three conditions in a termination made via WhatsApp, the termination may be deemed invalid without discussing the existence of a valid reason.

Note: Decisions from the same date are also known for their findings regarding the nature of WhatsApp correspondence as personal data (see section 6).

Istanbul Regional Court of Justice 29th Civil Chamber, 10.11.2017, E. 2017/3826, K. 2017/1524

While examining the plaintiff’s allegations that “the defendant company started terminating the employment contracts of workers employed in cleaning services by sending SMS messages to their mobile phones starting from August 30, 2016,” the provision “Article 19 of Law no. 4857 states that the employer must make the termination notification in writing and clearly and definitively state the reason for termination” was cited.

Principle derived from the decision: The allegation of collective dismissals being made via SMS was examined within the framework of the written and reasoned notification obligation in Article 19 of the Labor Law.

How is it used in practice?: The assessment valid for SMS messages also applies to WhatsApp messages: It is examined whether the message clearly and definitively contains the reason for termination and whether the other conditions in Article 19 are met.

Note: The source report does not contain information regarding the outcome of the decision; the full text should be examined via UYAP.

Constitutional Court, Appl. No: 2019/37012, 23.11.2022 (quoted from a secondary source)

In the first instance proceedings subject to the application, it was accepted that “the termination notice was not made in writing, and therefore the termination, which did not comply with the formal requirements, was invalid”; whereas in the retrial justification given in the decision, it was evaluated that “the written form requirement is not sought in the employer’s immediate termination for just cause, and the termination made due to the applicant’s actions was valid.”

Principle derived from the decision: Two different approaches are observed in the same file: In the first trial, the lack of written notification rendered the termination invalid; in the subsequent stage, it was accepted that the termination was an immediate termination for just cause, and that no written form was required for this termination.

How is it used in practice?: The legal nature of the employer’s termination and whether they can prove this nature determines the outcome. The employee should question what reason was stated at the time of termination, against the employer’s later characterization of the termination as “termination for just cause,” and whether the six-working-day period in Article 26 has passed.

Note: In the source report, this decision is mentioned both in terms of formal requirements and the examination of WhatsApp correspondence (see Section 6). The excerpts appear to belong to the parts where the Constitutional Court summarized the lower court proceedings. The applicant’s name and the outcome of the decision could not be independently verified; the full text should be examined from the Constitutional Court Decisions Database.

İzmir Regional Court of Justice 3rd Civil Chamber, 08.04.2026, E. 2026/538, K. 2026/742

Result: The decision for reinstatement was found to be erroneous.

In the event where the employee was sent a message via WhatsApp stating, “On the date the plaintiff was on leave, Ms. …[…] your employment has been terminated due to absenteeism. You do not need to come.”, it was determined that “the acceptance of the lawsuit and the decision for reinstatement are erroneous, without considering that there was no obligation for the defendant employer to send a warning notice to the plaintiff to inform them of their excuse, and given that the plaintiff’s termination declaration was reported to SGK with code 48 on 23/09/2024, and that the plaintiff’s employment contract was terminated for just cause by the defendant employer in accordance with Article 25/II-g of the Labor Law No. 4857.”

Principle from the Decision: The termination made via WhatsApp with the message “your employment has been terminated due to absenteeism” was evaluated as justified termination due to absenteeism (Art. 25/II-g); it was accepted that the employer is not obliged to send a warning notice to the employee to inform them of their excuse. The code 48 reported to SGK was taken into account as a fact supporting that the reason for termination was absenteeism.

How to apply in practice?: This decision shows that not every termination made via WhatsApp is automatically invalid: If the existence of a just cause (here, absenteeism) is proven, a formal deficiency may not change the outcome. From the employee’s perspective, documenting excuses (report, leave, correspondence) against an absenteeism claim is of vital importance.

Note: The quote states that the message was sent “on the date the plaintiff was on sick leave”. It should be examined from the full text of the decision whether the sick leave report covers the days counted as absenteeism, whether it was notified to the employer, and whether the period in Article 26 was observed; days on sick leave are not counted as absenteeism.

Supreme Court 9th Civil Chamber, 31.03.2016, E. 2015/27643, K. 2016/7929

With reference to the provision in Article 199 of the HMK, which states “Data in written or printed form, deeds, drawings, plans, sketches, photographs, films, video or audio recordings, as well as data in electronic environments and similar information carriers suitable for proving disputed facts, are documents according to this Law”, it was determined regarding declarations of intent in the form of messages not denied by the parties that “This declaration of intent sent as a message… which is not denied by the plaintiff, is generally valid; it does not need to be in the form of a petition and signed.”

Principle derived from the decision: A declaration of intent expressed via a message not denied by the opposing party is generally valid; it does not need to be in the form of a petition and signed.

How is it used in practice?: This principle is particularly important with regard to the employee’s termination (resignation) statement; because the Labor Law does not stipulate a written form requirement for the employee’s termination, as in Article 19. A “I resign” message sent in anger can have legal consequences. However, regarding the employer’s termination for a valid reason, the special conditions in Article 19 are additionally sought.

Note: The source report does not specify who sent the message or through which channel; the incident of the decision should be examined from the full text.

Istanbul 1st Civil Court of Commerce, 08.03.2024, E. 2022/294, K. 2024/162

“Upon examination of the correspondences submitted to the file by the plaintiff, which the defendant did not object to, it was stated that the defendant notified the plaintiff via a WhatsApp message that ‘it had decided not to continue working due to budgetary reasons’, and there was no notification that the plaintiff failed to fulfill its contractual obligation, thus the termination made by the defendant was unjust”; and the fact that “in the WhatsApp correspondences not denied by the defendant, it was communicated by the defendant to the plaintiff that the contractual obligations could not be fulfilled due to financial reasons” was accepted as evidence of the unjust nature of the termination.

Principle derived from the decision: An undeniable WhatsApp message proves both the intent to terminate and the reason for termination. If the reason is not the other party’s breach of contract, but the terminating party’s own budget problems, the termination has been deemed unfair.

How is it used in practice?: In an employment relationship, messages from the employer such as “we cannot continue due to costs” indicate that the termination is based on operational requirements, not the employee’s conduct; in this case, the employer must prove a valid reason based on operational requirements and that termination was the last resort.

Istanbul 4th Civil Court of Commerce, 07.05.2026, File No. 2024/42, Decision No. 2026/375

Result: The claim of de facto termination was not accepted.

“Although the plaintiff relied on messages and emails as the reason for termination, due to Article 16 of the contract stating that notifications must be made in writing via a notary public, and the defendant’s personnel wishing to continue working after a short work stoppage, the claim that the defendant de facto terminated the contract based on the emails and messages presented as evidence was not accepted.” — “The personnel’s short work stoppage of about 1 hour and their subsequent desire to continue working, while the plaintiff prevented the defendant’s personnel from working, does not mean that the defendant’s employees abandoned their jobs and that the contract was terminated.”

Principle derived from the decision: If it is stipulated in the contract that notifications will be made via a notary public, a message or email alone may not be considered a termination. Furthermore, a short work stoppage followed by a desire to continue working cannot be interpreted as de facto termination.

How is it used in practice?: If job contracts or workplace regulations stipulate that notifications must be made in a specific manner, it should also be evaluated whether a WhatsApp message meets this form.

Note: The spellings of “ilişkin” and “davalı” in the quote are as in the source.

Supreme Court 9th Civil Chamber, 10.01.2019, Docket No. 2018/10718, Decision No. 2019/559

Result: The rejection of severance and notice period compensation claims was found to be erroneous.

The WhatsApp system is “a system that facilitates communication via the internet in a phone and internet environment” and is in “a protected state, closed to third parties.” “It is essential that employees’ communications within this scope are also protected as personal data.” — “In the concrete dispute, since WhatsApp conversations constitute private personal data, terminating the employment contract solely based on these correspondences, whose acquisition method is unclear, is unjust, and rejecting the claims for severance pay and notice period compensation instead of accepting them is erroneous.”

Principle from the decision: Termination based on WhatsApp communications whose acquisition method cannot be understood is unjust.

How to use in practice?: The employee should request an explanation of how the screenshots presented by the employer were obtained.

Constitutional Court, Samet Ayyıldız, App. No: 2018/34548, 28.12.2021

Result: It was ruled that the right to respect for private life and freedom of communication were violated.

“In the concrete case, considering that the employer did not present any information or documents indicating that a notification showing the employer’s authority to examine the workplace computer and its scope was made to the applicant, it is understood that no clear information was provided regarding the monitoring and inspection of communication made through the computer allocated for workplace use by the employer.” — “On the other hand, the applicant’s employment contract was terminated citing WhatsApp message contents, which fall within the scope of private life. However, the employer, as the defendant, could not demonstrate during the trial process the legitimate reasons and grounds for the interference, that the applicant’s expectations were considered and their rights were taken into account, and furthermore, that the applicant was informed about the interference.”

Principle from the decision: WhatsApp communications on a workplace computer are part of the private sphere; the employer cannot terminate based on these contents without prior explicit notification.

How to use in practice?: The employee should inquire whether there was a prior written notification indicating the employer’s monitoring authority.

Constitutional Court, App. No: 2019/37012, 23.11.2022 (quoted from a secondary source)

“Firstly, it must be emphasized that in cases where no full and clear prior information is provided regarding the monitoring of communication made through a computer allocated for use in the workplace and the terms of use of communication tools, it is a foreseeable situation for the employer that the employee, with a legitimate expectation that their fundamental rights and freedoms will also be protected in the workplace, may engage in personal correspondence via the workplace computer.” — “Furthermore, it is clear that in the concrete case, the monitoring of the program, which is known by everyone and the employer to be for personal use, is contrary to the applicant’s reasonable expectation regarding the protection of their private life and the secrecy of their communication.”

Principle derived from the decision: Monitoring a program known to be for personal use is contrary to the employee’s reasonable expectation of privacy.

How is it used in practice?: As stated in the note in section 4, the full text of the decision should be examined separately.

Court of Cassation, 9th Civil Chamber, 01.06.2017, File No: 2016/14205, Decision No: 2017/9526

“Firstly, the WhatsApp system is a system that enables communication via the internet on phones and the internet environment. Here, individuals communicate with others, and communication is also carried out within groups by forming groups. However, this system is protected internally and closed to third parties. Therefore, as long as it does not disrupt the workflow of the employees and does not affect their work, it is not forbidden for them to form a group and communicate within it.” — “Employees’ emails and notifications to the employer at the workplace are in the nature of democratic demands regarding labor rights, and it is not correct to make such peaceful behaviors a reason for termination. The defendant employer, who bears the burden of proof, could not prove a just and valid termination.”

Principle derived from the decision: As long as it does not disrupt the workflow of employees, forming a WhatsApp group is not prohibited. Peaceful and democratic demands regarding labor rights cannot be a reason for termination.

How to use in practice?: Employees terminated due to group correspondence regarding wages, overtime, or working conditions can rely on this decision; such a termination may also be associated with the prohibition of termination for pursuing rights under Article 18 of the Labor Law.

Note: Typographical errors in the quotation are as in the source.

Constitutional Court, App. No: 2019/33833, 20.07.2023

The lower courts evaluated that the applicant’s shares fell within the scope of “a valid reason arising from the employee’s competence or conduct” as per Article 18 of the Labor Law. However, the Constitutional Court stated the principle that “According to the ruling, conduct can only be considered a valid reason if it leads to negative consequences at the workplace. If the employee’s conduct does not have a negative impact on the production and employment relationship process at the workplace, it is not possible to cite such conduct as a valid reason for the termination of the employment contract.”; and stated that “Although the Court concluded that the applicant set a negative example for employees due to the cartoon shared in the WhatsApp group, it was overlooked that the entire group consisted of a certain number of individuals in managerial positions at the same level as the applicant” and “In the specific case, it was not alleged that the shares subject to the application were made during working hours or with work tools or at the workplace, and that the applicant failed to fulfill their responsibilities arising from the employment contract for these reasons”.

Principle derived from the decision: Conduct can only be a valid reason for termination if it causes negativity at the workplace. When evaluating whether a share in a WhatsApp group can be considered a valid reason, factors such as who constitutes the group, whether the share was made during working hours, with work tools, or at the workplace, and whether the employee neglected their work responsibilities should be considered.

How is it used in practice?: In terminations made due to shares outside working hours, from a personal phone, and in a limited group, the employee must emphasize that the share did not lead to a concrete negative impact at the workplace.

Note: It is observed that the Constitutional Court criticized the evaluation of the lower courts; as it is not stated in the source report regarding which right and with what outcome the decision was rendered, the full text should be checked from the Constitutional Court Decisions Database.

Court of Cassation, 9th Civil Chamber, 15.01.2020, App. No. 2019/7066, Dec. No. 2020/357

Result: The rejection decision, given on the grounds of just cause, was overturned; the termination was deemed based on a valid reason.

“When the information and documents in the file and the statements of the party witnesses are evaluated, it is evident that the plaintiff sent an obscene message in a WhatsApp group formed by some of the employees.” Since the target of the message was not clarified, “Although the termination was not based on just cause, it was understood that the plaintiff’s actions led to a negative situation at the workplace and that the termination, even if not based on just cause, was based on a valid reason, therefore, instead of rejecting the case on this ground, its rejection on the ground that the employment contract was terminated for just cause is erroneous, and thus it was necessary to overturn and annul the decisions of the Court of First Instance and the Regional Court of Justice.”

Principle from the decision: An offensive (obscene) message sent in a WhatsApp group by employees, if its target is not specific, may not constitute just cause; however, since it leads to negativity in the workplace, it can be considered a valid reason.

How is it used in practice?: The distinction between termination for just cause and termination for valid reason directly affects compensation: In termination for just cause, severance and notice pay are not paid; however, in termination for valid reason, they are paid, but the request for reinstatement is rejected. It should not be forgotten that in termination for valid reason, the employer must also have fulfilled their obligations of written notification and obtaining a defense as per Article 19 of the Labor Law.

Supreme Court 9th Civil Chamber, 28.11.2018, File No. 2018/2785, Decision No. 2018/21795

Result: The termination was deemed based on just cause.

“In the specific dispute, from the information and documents within the file; the incident that led to the termination of the employment contract was the plaintiff’s insulting another employee of the defendant, […], via phone message, and it is established that this situation constitutes a just cause for termination for the employer under Article 25/II-d of Labor Law No. 4857.” — “Since the words uttered by the plaintiff were of an abusive nature, the termination carried out by the employer is based on just cause.”

Principle derived from the decision: An employee’s insulting another employee via phone message is considered harassment/abuse under Article 25/II-d and constitutes a just cause for termination.

How is it used in practice?: An employee who has been insulted forwarding the message they received to the employer is evaluated differently from a third party covertly obtaining it. In this situation, the employer must also exercise their right to terminate within the six working day period specified in Article 26.