Fraud Offense Committed by Using Information Systems or Banks and Credit Institutions as Instruments

In today’s world, where technology is developing rapidly, classical methods of crime have given way to acts carried out through more complex and digital tools. The Turkish Penal Code has kept pace with this transformation by regulating the commission of the offense of fraud through “information systems” or “banks and credit institutions” as a “qualified (aggravated) form” of the offense, due to the ease of commission and the significant social harm it creates. Foreseeing the risks brought about by technology, the legislator has subjected such acts to heavier criminal sanctions.

The Offense of Fraud

Although the offense of fraud is essentially a crime against property, it differs from offenses such as theft or breach of trust in that it also targets the victim’s freedom of will. For the offense of fraud to be constituted, the perpetrator must deceive another person through fraudulent acts capable of misleading, and as a result of this deception, must obtain an unlawful benefit for himself or another person, to the detriment of the victim or a third party.

The main element distinguishing this offense from other property crimes is that the act is based on deception. The legislator has refrained from defining the concept of fraud, leaving its determination to doctrine and judicial practice. However, according to the case law of the Court of Cassation (Yargıtay), fraud is defined as a “qualified lie.” A mere simple lie does not constitute fraud; rather, the fraudulent conduct must be of a certain gravity, intensity, and sophistication, and must be capable of eliminating the victim’s opportunity for verification.

For the offense to be established, the following conditions must coexist:

• The perpetrator must engage in fraudulent conduct,

• Such conduct must be capable of deceiving the victim,

• As a result of this conduct, the perpetrator must obtain an unjust benefit to the detriment of the victim or another person.

Use of Information Systems and Banks as Instruments

The commission of the offense of fraud through information systems or banks is regulated as a qualified form under Article 158/1-f of the Turkish Penal Code. The fundamental rationale for this regulation lies in the convenience, speed, and effect of trust these instruments create on victims.

a. Information Systems as Instruments

An information system is defined as a magnetic system that enables the automatic processing of data after it is collected and stored. Today, internet banking, e-commerce platforms, and social media platforms fall within this scope. The use of such systems as instruments of crime facilitates the concealment of the perpetrator’s identity and enables reaching a large number of victims simultaneously.

An information system itself cannot be deceived. If a perpetrator accesses a system and alters data to obtain a benefit without deceiving a human being, such conduct constitutes a cybercrime or theft committed through the use of information systems. For the provisions on fraud to apply, it is mandatory that a real person be deceived through the use of the system as an instrument.

Online marketplace fraud and fraud committed through false online listings are the most common methods involving information systems (websites, social media). The perpetrator advertises a vehicle, electronic device, or holiday service that he does not actually possess, offering it at an attractive price. Trust is created through photos, videos, and fake reviews enabled by the information system. After receiving money under the guise of a “deposit” or “purchase price,” communication is cut off. In such cases, the information system is the primary instrument for reaching and deceiving the victim.

Court of Cassation (Yargıtay) 15th Criminal Chamber

Merits No. 2017/9901, Decision No. 2019/15168

In the incident where the defendant posted an online listing for sale of an HP-brand laptop on the website www.sahibinden.com; the complainant contacted the defendant after seeing the listing; the parties agreed that 300 TRY would first be sent via PTT and that the remaining amount would be paid upon receipt of the package from the cargo company; the complainant sent the 300 TRY; upon opening the package received from the cargo company, it was found to contain a ream of A4 paper instead of a computer; and the defendant could no longer be contacted—rendering a conviction for simple fraud by mischaracterizing the legal nature of the act, without considering that the defendant’s conduct constituted aggravated fraud committed through the use of information systems pursuant to Article 158/1-f of the Turkish Penal Code, is contrary to law.

Court of Cassation (Yargıtay) 11th Criminal Chamber

Merits No. 2021/15203, Decision No. 2021/10106

In the public prosecution initiated on the allegation that the defendant committed the offense of fraud, where the complainant saw an online listing for sale of a vehicle on an internet website, called the telephone number provided in the listing, reached an agreement following negotiations conducted by phone, and sent the requested 100 TRY deposit to the specified bank account; and where, upon subsequently calling the same telephone number, the complainant’s calls went unanswered; considering that the defendant posted an online listing on an internet website and obtained a benefit from the complainant through this system, it is established that the internet, as an information system, was used as an instrument—rendering a conviction for simple fraud by mischaracterizing the legal nature of the act, without taking into account that the conduct constituted the offense of fraud committed through the use of information systems pursuant to Article 158/1-f of the Turkish Penal Code, is contrary to law.

Court of Cassation (Yargıtay) 11th Criminal Chamber

Merits No. 2021/13431, Decision No. 2021/6697

In the public prosecution initiated on the allegation that the defendant committed the offense of fraud, where, on the date of the incident, the complainant decided to take a holiday at … Hotel, operating in the Alanya district through the intermediation of … Tourism, after researching hotels online; contacted the telephone numbers listed on … Tourism’s website and spoke with the defendant, who introduced himself as …; upon reaching an agreement, the complainant, prior to making any reservation, transferred 630 TRY, corresponding to the accommodation fee for four nights, to the defendant’s bank account held at … Bankası A.Ş., … Branch; whereupon the defendant stated that he would initiate the procedures and send a fax, but the complainant was subsequently unable to reach the defendant—considering that the defendant posted an online listing on an internet website and obtained a benefit from the complainant through this system, and that the internet, as an information system, was used as an instrument; rendering a conviction for simple fraud by mischaracterizing the legal nature of the act, without taking into account that the conduct constituted the offense of fraud committed through the use of information systems pursuant to Article 158/1-f of the Turkish Penal Code, is contrary to law.

Court of Cassation (Yargıtay) 11th Criminal Chamber

Merits No. 2021/17211, Decision No. 2024/11892

In the case where the defendant posted an online listing for a rental villa on an internet website, requested a 200 TRY deposit after the complainant contacted him by telephone, received the said amount from the complainant, and thereafter could no longer be contacted; given that it is established that the defendant’s conduct constituted the offense of fraud committed through the use of information systems pursuant to Article 158/1-f of the Turkish Penal Code, rendering a judgment based on an erroneous legal assessment under Article 158/1-g of the same Code is contrary to law.

Court of Cassation (Yargıtay) 15th Criminal Chamber

Merits No. 2017/23355, Decision No. 2020/5325

In the incident where the defendant posted an online listing for the sale of a mobile phone on the website …market.com; the complainant, upon seeing the listing, contacted the defendant and placed an order for the mobile phone; the complainant paid 170.00 TRY as payment upon delivery for the cargo sent by the defendant; upon opening the package, it was discovered that it contained headphones instead of a mobile phone; and the defendant could thereafter no longer be contacted—rendering a conviction for simple fraud by mischaracterizing the legal nature of the act, without taking into account that the defendant’s conduct constituted the offense of aggravated fraud committed through the use of information systems or banks and credit institutions as instruments pursuant to Article 158/1-f of the Turkish Penal Code, is contrary to law.

b. Banks or Credit Institutions as Instruments

The use of banks or credit institutions as instruments means that the perpetrator exploits the institutional trust these entities enjoy in society. However, not every use of a bank constitutes this qualified form. For the offense to occur, the bank’s ordinary activities or the instruments associated with such activities (such as checks, credit cards, letters of guarantee, etc.) must be used as deceptive tools.

If a bank is used merely as a means of payment (for example, the transfer of defrauded money via bank transfer), this qualified form may not apply. What is essential is that the perpetrator deceives the victim by using the existence, identity, or materials of the bank (such as a forged check or fake bank receipt) as the instrument of fraud.

Forged bank checks, letters of guarantee, or credit cards may be produced and circulated in the market. The victim delivers property relying on the belief that the document is a genuine bank instrument. In such cases, the bank’s corporate identity and documentation constitute the core elements enhancing the credibility of the deception.

Court of Cassation (Yargıtay) 15th Criminal Chamber

Merits No. 2021/1625, Decision No. 2021/7237

Although, in his defenses, the defendant stated that he had obtained the check forming the subject matter of the offense from the complainant’s partners and that he was unaware that the check was forged, it is understood that he was unable to provide any concrete information sufficient to identify the persons from whom he allegedly obtained the check, such as clear identity and address details; that he failed to explain the legal relationship on the basis of which he received the check; that his statements on this matter were contradictory at different stages of the proceedings; and that he could not submit any invoice, delivery note, or document in support thereof. Accordingly, since the defendant’s act—consisting of delivering to the complainant, in the course of their commercial relationship, a forged check having the capacity to deceive and containing all constituent elements—was established, rendering an acquittal as written instead of a conviction for the offense of fraud committed by using information systems, banks, or credit institutions as instrumental means is contrary to law.

Court of Cassation (Yargıtay) 11th Criminal Chamber

Merits No. 2021/21036, Decision No. 2025/6589

In the incident alleged that the defendant delivered to the complainant, in consideration of animal feed purchased from the complainant, the check forming the subject matter of the offense in the amount of TRY 6,850, which was entirely forged, and that upon presentment of the check to the bank it was determined to be forged; given that the defendant failed to prove the identity of the person from whom he claimed to have obtained the check and that he obtained unjust benefit by delivering to the complainant a check that was entirely forged, it is understood that, while a conviction should have been rendered against the defendant for the offense of fraud committed by using information systems, banks, or credit institutions as instruments pursuant to Article 158/1(f), last paragraph, of the Turkish Penal Code No. 5237, rendering an acquittal is contrary to law.

Court of Cassation (Yargıtay) 15th Criminal Chamber

Merits No. 2014/24029, Decision No. 2017/11311

As it is understood that the defendant committed the offense by using a forged check, without considering that the act constitutes the offense of fraud committed by using information systems, banks, or credit institutions as instruments under Article 158/1(f) of the Turkish Penal Code, and by falling into an error in the legal characterization of the offense and rendering a judgment pursuant to Article 158/1(h) of the same Code—fraud committed during commercial activities by a merchant or a company executive, or by a person acting on behalf of a company—the decision as written is contrary to law.

Statutory Basis of the Offense, Penalty, and Legal Consequences

Article 158/1-f of the Turkish Penal Code No. 5237 regulates the offense of fraud committed through the use of information systems or banks and credit institutions as instruments. Under this provision, the minimum term of imprisonment has been increased through recent legislative amendments to four years, and the sentence may extend up to ten years. In addition to imprisonment, the court shall impose a judicial fine of not less than twice the amount of the unlawful benefit obtained.

Personal Circumstances Which Reduce or Abolish the Penalty and Effective Remorse

In the case of the offence of qualified fraud committed through the use of information systems or banks as instruments, the legislator has given special consideration, in terms of criminal justice, to the kinship relationships between the offender and the victim as well as the positive conduct of the offender after the commission of the offence.

a. Personal Circumstances Which Reduce or Abolish the Penalty (Article 167)

Where the offence of fraud is committed to the detriment of a spouse not subject to a court decree of separation, a direct antecedent or descendant, a relative of the same degree by marriage, an adoptive parent or adopted child, or a sibling residing in the same household, no penalty shall be imposed on the offender. Where the offence is committed to the detriment of a spouse subject to a court decree of separation, a sibling not residing in the same household, or an uncle, aunt, nephew, niece, or second-degree relative by marriage residing in the same dwelling, the penalty to be imposed shall be reduced by one half, upon complaint. This provision constitutes a form of personal immunity from punishment introduced for the purpose of protecting family ties.

b. Effective Remorse (Article 168)

After the completion of the crime of aggravated fraud, but before a lawsuit is filed, if the perpetrator, instigator, or accomplice personally shows remorse by fully restoring the loss suffered by the victim or compensating for it, the sentence to be imposed shall be reduced by up to two-thirds. If effective remorse occurs after the lawsuit has been filed (but before the judgment is rendered), the sentence may be reduced by up to one-half. The crucial point is that the restoration of the loss must be based on the free will of the perpetrator and that the decrease in the victim’s property is fully remedied. In cases of partial restoration or compensation, the application of effective remorse provisions requires the consent of the victim.

Criminal Investigation and Prosecution Process

The crime of fraud committed through the use of information systems or banks as instruments (Turkish Penal Code, Art. 158/1-f) is, as a rule, prosecuted ex officio and is not subject to any complaint period. However, an exception exists under Article 167/2 of the Penal Code regarding “family relationships”; if the crime is committed against relatives specified in this article (such as siblings living separately, uncles, nephews, etc. residing in the same household), the initiation of an investigation depends on a formal complaint.

Reconciliation (Uzlaştırma): The aggravated fraud offense regulated under Penal Code Art. 158/1-f is not subject to reconciliation. Although the basic form of fraud (Art. 157) may be eligible for reconciliation, when information systems or banks are used as instruments, a public prosecution is commenced ex officio without requiring a complaint.

Competent Court: With the Law No. 7571 published in the Official Gazette on 25.12.2025 and the subsequent High Council of Judges and Prosecutors (HSK) Decision dated 27 December 2025 (No: 2275), a significant change in jurisdiction was introduced for these crimes. According to the decision, the specialized jurisdiction of heavy penal courts for adjudicating aggravated fraud under Art. 158 has been abolished. Under the new regulation, cases arising from these offenses will now be distributed equally among local Criminal Courts of First Instance (Asliye Ceza Mahkemesi) through general assignment.

Authorized Court: While the court of the place where the crime was committed is generally the authorized court, in cases involving the use of information systems, the court of the victim’s place of residence may also be considered an authorized court.