Does copying software constitute copyright or patent infringement?

Entrance

In the digital age, software is not just a tool, but the heart of companies' intellectual capital. However, the legal framework for protecting software remains unclear to many professionals. Software copying is a common occurrence. In such cases, would copying constitute copyright infringement or patent infringement?

The answer to this question depends on many variables, such as the nature of the software, its content, and which elements are being copied. Below, we will address this distinction from both theoretical and practical perspectives, offering a unique approach.

1. How Software is Protected Under Turkish Law

Copyright Protection

In Türkiye, software is protected as a "computer program" under the Law No. 5846 on Intellectual and Artistic Works ("FSEK"). This protection applies to software that:

• Source code,

• Object code,

• Interface design,

• Like a database structure,

It includes these elements. Protection begins at the moment the work is created. Registration is not mandatory.

Patent Protection

The Industrial Property Law No. 6769 ("IPL") protects inventions that provide a technical solution to a technical problem. Software cannot be patented solely due to its algorithmic structure. However, software that works integrated with a device and has a technical outcome (for example, a control system that manages a robotic arm) can receive patent protection.

2. Copyright or Patent? – The Theoretical Distinction

The Nature of Copyright

Copyright protects the expressive form of a work. Therefore, copying software code verbatim, or exhibiting similarities in order and structure, constitutes copyright infringement.

Elements protected under copyright:

• The original structure of the code,

• Interface designs,

• Data processing sequences (provided they are original).

The Nature of Patent Protection

A patent is based on an intellectual property and technical solution. Software is only eligible for patent protection in the following cases:

• If it is a functional part of a physical system,

• If it solves a technical problem and can be applied in industry,

• If it works in an integrated way with a physical device.

In other words, a patent protects "what the software does and what technical benefit it provides," not "how the software works.".

3. Practical Application – Fictional Case Study

Event Summary:

E Yazılım Ltd. Şti. has registered the copyright for its self-developed accounting software and has also applied for a patent for a special algorithm used in the program's data processing module. This software generates customized quotation and invoice reports for companies.

In 2025, F Teknoloji A.Ş. releases software called "HızlıMuhasebe" (Fast Accounting). Despite seemingly different interfaces, it's noticed that it uses E Yazılım's patented algorithm similarly and produces the same data results. Furthermore, numerous line-by-line similarities are identified in the source code.

E Software's Legal Strategy:

1. Request for Declaration of Infringement:
   The software's source code and operation are examined by a technical expert, and a lawsuit is filed to determine whether there is both patent and copyright infringement.

2. Copyright Lawsuit: A
   copyright infringement lawsuit is filed under Articles 71 et seq. of the Law on Intellectual and Artistic Works due to the verbatim copying of certain parts of the code. In this lawsuit:

   • It must be proven that the code was obtained using identical or similar structures.

   • The damages resulting from the application's use in the market are calculated.

   • A court order for prohibition, injunction, compensation, and destruction of the property is requested.

3. Patent Rights-Based Lawsuit:
   Since the algorithm is also patented, a patent infringement lawsuit can be filed under Articles 141 et seq. of the Industrial Property Law. Here;

   • It is demonstrated that the patented design is used in its original or equivalent form.

   • The sale of the product is stopped and the profits earned are returned.

4. Criminal Investigation:
   Under Article 71 of the Law on Intellectual and Artistic Works, a criminal investigation will be initiated due to the unauthorized use of the software.

Evaluation:

In this case, both copyright and patent rights have been infringed. However, a copyright lawsuit was filed for the copied code portion, and a patent lawsuit was filed for the algorithmic structure and functional system. It is possible for software to be the subject of litigation under two protection regimes simultaneously.

4. Problems Encountered in Practice

• Proof of code authenticity: Technical expert reports will be decisive in determining whether code similarities are coincidental or intentional.

• Narrow interpretation of the patent field: In Türkiye, the patent protection of software is interpreted quite narrowly. Technical impact is sought, and mere algorithms are excluded from scope.

• The limit of interface similarity: Although interface design is generally considered under copyright law, courts do not issue infringement rulings for similarities that do not reach a certain threshold.

• Length of the trial process: Both technical expert examinations and comprehensive compensation calculations prolong the proceedings.

5. Legal Advice

• Register the code with a notary as soon as you develop the software. This provides a significant advantage in terms of proof.

• Archive all versions of the code with dated records. Maintain a change log and document the source files.

• If the software provides a technical solution to a technical problem, don't neglect to apply for a patent. The method, but not the code, can be protected.

• Clearly state ownership rights in contracts. In employer-employee relationships, ownership of software can be a source of dispute.

Conclusion

Copying software often constitutes copyright infringement. If the code is used identically or functionally, Law No. 5846 applies. However, if the software solves a technical problem and works in conjunction with a device, then patent infringement may also be a concern. Copyright protects the expression of an idea, while a patent protects the technical solution to that idea. In practice, where these two rights intersect, careful consideration should be given, and each right should be protected separately.

Gamze Akbulut, Law Faculty Student