Legal and source review date: 5 October 2026. This guide provides general information. The applicable powers, deadlines, procedural options, privilege position, fine exposure and judicial remedy depend on the served documents, the conduct under review, the entities involved and the law in force for the matter.

1. Start with the Turkish market effect and the document actually served

Law No. 4054 on the Protection of Competition applies to undertakings operating in Turkish goods and services markets and to conduct that affects those markets. A foreign parent, regional headquarters or overseas sales team should therefore not treat the absence of a Turkish-incorporated contracting party as a complete jurisdictional answer. The first question is whether the agreement, practice, decision or conduct has a sufficient connection with competitive conditions in Türkiye. That analysis requires the relevant product or service, geography, sales route, customers and group entities; it should not be replaced by the assumption that every foreign act falls within Turkish jurisdiction.

When the Turkish Competition Authority contacts a group company, build a matter map before preparing a narrative. Record the addressed legal entity, every business unit mentioned, the alleged period, Turkish market contacts, custodians, reporting lines and the systems likely to hold responsive information. Keep the Authority’s procedural step separate from the merits. A preliminary inquiry or a Board decision to open an investigation is a serious event, but it is not a final finding that the company infringed competition law. Internal and external communications should preserve that distinction.

The investigation notice and the documents validly served should control the issue list and calendar. A board update should distinguish allegations, procedural decisions, evidence-preservation work, statutory ceilings and scenario estimates. Combining those categories can create avoidable legal and accounting problems. A maximum statutory percentage is not a forecast; a request for information is not an infringement decision; and a procedural fine issue does not establish the suspected substantive conduct.

This guide concerns the response to an Authority inquiry or investigation. It does not explain merger notification, turnover thresholds, lasting control or transaction clearance. Those questions belong to a dedicated merger-control analysis and, for acquisitions, to Buying a Turkish Company: Legal Due Diligence Guide. A transaction can later become the subject of an investigation, but notification analysis and investigation response remain different legal exercises.

2. Information requests: control the deadline, facts and production record

Under Article 14 of Law No. 4054, the Authority may request information it considers necessary to perform its statutory duties, and the addressee must respond within the period set by the Board. There is no safe generic internet deadline. The response team should authenticate the request, identify how and when it was served, preserve the complete attachment set, note the named recipient and calculate the deadline from that document. Any extension request, clarification or procedural direction should be retained with the same audit trail.

The business should answer from source records, not memory. Divide the request into numbered questions; assign an owner and reviewer; identify the systems and date ranges searched; and reconcile statements with contracts, invoices, pricing records, minutes, emails and data extracts. If information is unavailable, explain the search and the reason rather than guessing. Translation should be controlled so that the English working version and Turkish response express the same facts. The final production index should show what was supplied, in which format and on what date.

Incomplete, incorrect or misleading information, or a failure to provide requested information within the prescribed period, may lead to a procedural fine calculated at one per thousand of the statutory annual gross-revenue base. The relevant entity, financial period and revenue base must be established from the law and records. Group revenue, Turkish revenue and the revenue of the addressee are not interchangeable assumptions. A working estimate should state its inputs and uncertainties rather than present a number as settled.

For a multinational group, an English translation is a working aid. The authenticated Turkish request or decision governs its scope, deadline and remedies. Before submission or publication, each statement about fines, privilege, settlement, commitments, leniency or court review should be checked against the current official Turkish text. The same rule applies to templates: a response used in another jurisdiction may help organise work, but it cannot import foreign privilege rules, production limits or procedural timetables into Türkiye.

3. On-site inspection: procedural controls during the first hour

Article 15 permits authorised experts to examine books, physical records, electronic data and information systems, take copies and physical samples, ask for written or oral explanations on particular matters, and inspect assets on site. The company should be ready to cooperate while keeping a precise record of what occurs. This section gives the wider investigation context. The Turkish-language analysis of Competition Board on-site and digital inspections remains the detailed treatment of inspection technology, obstruction and related practice.

At arrival, reception should contact the designated legal and IT response team immediately. A responsible employee can verify the experts’ identity and the authorisation document, which should state the subject, purpose and consequence of incorrect information. Verification must be prompt and must not become a device for delay. Law No. 4054 also provides for inspection under a magistrate judge warrant where an inspection is obstructed or is likely to be obstructed. Whether a warrant is required on a particular record is a legal question; staff should not improvise a universal answer at the door.

Issue an immediate preservation instruction. Nobody should delete, edit, hide, move or remotely wipe responsive information after inspectors arrive. Suspend routine deletion where technically possible and tell remote administrators not to change access, devices or accounts. The Pirelli decision shows the exposure created by post-arrival deletion, while Pirelli and NAOS both illustrate how employee conduct affecting access to company devices can create company-level procedural risk. Recovery of data later does not make the original conduct harmless.

Create a contemporaneous inspection log. Record arrival and departure, names and roles, areas visited, devices and accounts examined, search terms or methods described, explanations requested, objections raised, privilege claims, copies or samples taken, interruptions and signatures. Preserve access, deletion, device-custody and system logs from the moment the inspection is known. The record should be factual and neutral; it is not a running advocacy document and should not interfere with the inspectors’ work.

The response team can use this first-hour sequence:

Notify legal, IT, records and a senior business contact without creating delay.
Verify the authorisation document and identify the investigation’s stated subject.
Issue a no-deletion and no-remote-interference instruction to on-site and remote personnel.
Provide suitable workspace and identify an employee who can explain systems accurately.
Keep one factual log and one copy set of material delivered or copied, where permitted.
Escalate privilege questions document by document and record the basis without obstructing access.
Preserve the inspection record for the investigation, defence and any procedural-fine review.

4. Digital evidence, devices and obstruction risk

Digital evidence work is concerned with access, completeness and integrity. In Pirelli, the Board treated deletion of WhatsApp material after the inspection team arrived as significant even though material was recovered from other devices; recovery did not eliminate uncertainty about what had been removed or whether the record was complete. In NAOS, device and SIM handling, an apparently blank phone and telecom evidence formed part of the obstruction assessment. These are fact-specific Board decisions, not automatic rules, but they show why device custody and chronology matter.

Obstructing or making an on-site inspection difficult may trigger a procedural fine calculated at five per thousand of the statutory annual gross-revenue base. Law No. 4054 also contains a daily relative fine of five ten-thousandths for specified continuing non-compliance or obstruction situations. Daily exposure should not be added automatically: the statutory trigger and start date must be identified. A later court-assisted inspection does not by itself erase earlier conduct that the Board considers obstructive.

The legal status of the Authority’s 2020 digital-inspection guide remains unresolved. On 5 October 2026, its former official URL returned HTTP 404 and the current official guidelines index did not list that title. The 2025 Pirelli decision records that the Authority referred the undertaking to the guide, while the Authority’s 2025 Annual Report states that work on a new on-site inspection regulation and guide was ongoing. The missing page and index entry do not establish revocation, replacement or continuing legal effect. The analysis therefore rests on Law No. 4054 and current official decisions, and the guide’s status is recorded as unresolved rather than inferred.

Cross-border IT coordination needs a single command structure. Turkish counsel, regional legal, forensic personnel and information-security staff should agree who can authorise access, suspend deletion, preserve cloud logs and communicate with inspectors. A foreign blocking rule, data-transfer concern or privilege label may require analysis, but it should not be asserted reflexively. The team should identify the precise conflict, preserve the evidence and seek a controlled solution under the applicable Turkish process.

5. Legal privilege is narrow and document-specific

The Competition Board’s Tatko decision describes protection for communications between an independent lawyer and client that are made for the exercise of defence rights. The test is functional and document-specific. A file name, “privileged” stamp or placement in a legal folder does not determine the result. For each disputed item, the team should identify the participants, purpose, timing, subject and direct relationship to the exercise of defence rights.

Tatko also explains the limits of the Board’s approach. Communications unrelated to defence rights, or communications used to facilitate or conceal an existing or future infringement, do not receive protection under that test. Material created before an investigation is not automatically protected merely because a lawyer participated. Timing is relevant, but the content and purpose remain central. Tatko is an official Board decision and may be judicially reviewed; it is not a comprehensive statutory privilege code.

In-house counsel communications are not automatically protected under the independent-lawyer formulation used by the Board. That does not justify the opposite generalisation that every in-house communication is unprotected. The correct response is to examine the particular document, the lawyer’s role and independence, the defence purpose and current judicial authority. Foreign-law privilege designations should be recorded, but they should not be assumed to control the Turkish inspection.

As an internal response practice, the company can maintain a concise privilege log stating the item, participants, date, purpose and asserted defence nexus without disclosing the substance said to be protected. Tatko does not prescribe that format. It is a control tool for consistent decisions and later review, and it should be adapted to current procedural instructions. Broad, unsupported claims can undermine credibility; failing to identify a genuine defence communication promptly can prejudice the company’s ability to preserve and present the issue.

6. From investigation notice to file access and defence

Access to the investigation file is part of the defence framework under Article 44 of Law No. 4054 and Communiqué No. 2010/3. The communiqué was amended on 4 October 2025, but its Provisional Article 1 excludes investigations already ongoing from those amendments. The date on which the Competition Board decided to conduct or open the investigation must therefore be established before applying the later form, timing or access provisions. That event is distinct from later notification or service, and publication should not present the amended text as governing every open file.

File access and trade-secret treatment are connected but separate. A confidentiality claim does not automatically remove information from all procedural use, and access rights do not eliminate protection for material properly classified as confidential. The company should identify precisely which passages contain trade secrets, explain the commercial harm and propose a workable non-confidential treatment where the rules permit. Overdesignation can delay review and distract from material confidentiality issues.

The written defence stages must be calendared from the notice, the investigation report and other valid service events under the current law. A website should not give a personal deadline without those records. Law No. 4054 also provides for an oral hearing on request or on the Board’s own initiative. Whether to request one depends on the contested facts, economic analysis, documentary record and what can be clarified effectively at a hearing; it is not an automatic final step in every matter.

Enforcement activity is substantial but varied. The Authority’s 2025 Annual Report records 44 completed investigations and 1,509 on-site inspection assignments during that year. It also reports ordinary infringement decisions, settlements, commitments and no-infringement outcomes. These figures give historical context only. They do not predict how the Board will classify a new matter, accept a procedure or calculate a sanction.

7. Sanctions: keep procedural exposure and substantive liability separate

Law No. 4054 uses different sanction structures. The absolute minimum for certain procedural fines is revalued annually, so the current official figure must be checked for the relevant decision date and should not be hardcoded into a durable guide. For a substantive infringement of Articles 4, 6 or 7, Article 16 permits a fine up to ten percent of the applicable annual gross-revenue base. “Up to” identifies a ceiling; it does not establish the likely amount.

For decisions made between 1 January and 31 December 2026, Communiqué No. 2026/1 sets the minimum administrative fine under Article 16(1) of Law No. 4054 at TRY 302,484.86. This is a dated statutory minimum, not an estimate of any undertaking’s exposure; a decision in another year requires the official figure applicable on that decision date.

Managers and employees found to have a determining effect may face a fine up to five percent of the fine imposed on the undertaking or association. That possibility should be explained carefully. Individual exposure requires findings about role and effect, and the active-cooperation regime may treat individuals differently depending on the application, sequence, evidence and compliance. The existence of an investigation does not itself establish individual liability.

The 2024 Fine Regulation and 2025 Fine Guideline address the calculation of substantive fines and must be read with Law No. 4054. The guideline explains the Authority’s stated approach but does not override the Law or regulation and does not turn discretionary assessment into a fixed calculator. A responsible estimate identifies the alleged infringement, duration, revenue inputs, possible aggravating or mitigating factors and unresolved facts. It should not be marketed as a quote for the final sanction.

Procedural fines for information failures or inspection obstruction should also remain separate from the merits. A company may contest a procedural decision while defending the substantive case, and the relevant facts, bases and remedies can differ. The internal reserve discussion, public statement and court petition should each use the correct decision and revenue period rather than combining every theoretical maximum.

8. Commitments, settlement and leniency serve different purposes

Commitments can address competition concerns arising under Articles 4 or 6 during a preliminary investigation or investigation. They are not available for conduct classified as a clear and hard infringement under the governing rule. Before proposing a remedy, the company should define the concern, test whether the route is legally open, assess whether the remedy is proportionate and decide how compliance can be demonstrated. An offer copied from another market may not address the Turkish theory of harm.

If accepted, commitments become binding and can close the proceeding as to the addressed concerns without an infringement finding. That outcome is not unconditional finality. The Board may reopen when material facts change, a commitment is breached, or the decision rested on incomplete, incorrect or misleading information. Governance should therefore assign owners, evidence, reporting and escalation for each accepted obligation.

Settlement is an investigation-stage mechanism, not a general pre-investigation clearance. The timing window includes the service boundary for the investigation report, and the current regulation and case documents must be read before calculating the last available day. Early evaluation should include the strength of the evidence, the range of possible fine consequences, disclosure and follow-on risks, multi-jurisdictional consistency and the value of procedural closure.

Settlement requires admission of the existence and scope of the infringement addressed by the settlement. The Board may grant a reduction of up to twenty-five percent, but the maximum is not an entitlement. The settling party cannot sue over the matters contained in the settlement text or the administrative fine imposed through settlement. The exact wording therefore matters: an admission can affect contractual, civil and foreign proceedings even though those effects are not determined by the settlement regulation alone.

Active cooperation, commonly described as leniency, is designed for detecting cartels. It is not a general discount programme for every competition concern. Current analysis starts with the 2023 Active Cooperation Regulation, while respecting its Provisional Articles 1 and 2. The new three-month rule does not apply to investigations opened before 16 December 2023, and applications filed before effectiveness retain the stated former-regulation conditions and procedure with applicant-favourable reduction rates. The chronology of investigation and application is therefore essential. The outdated 2013 guide should not be presented as the current source.

The 2023 regime addresses undertakings and, in defined circumstances, managers and employees who cooperate. Immunity or a reduction depends on sequence, evidence and continuing compliance. No company should be promised immunity, a particular reduction, settlement acceptance or commitment acceptance before the legal conditions and evidentiary record have been tested. These routes can also create tensions between corporate and individual interests that require separate advice.

9. Reasoned decision, court action and interim relief

A Board decision may be challenged before the competent administrative court. Filing the action does not automatically suspend implementation of the decision or collection of an administrative fine. The court file therefore needs two separate analyses: the grounds for annulment and whether interim protection should be requested. Venue, standing, the reviewable act and the scope of each claim must be checked against the reasoned decision and current procedural law.

Under Article 27 of Administrative Procedure Law No. 2577, a stay of execution generally requires both clear unlawfulness and irreparable or impossible harm, supported by a reasoned order. Repeating the merits allegations is not enough. The application should connect identified legal defects with concrete enforcement consequences, while recognising that the court decides both limbs on the particular record. A stay should never be described as automatic or assured.

The general period for an action in the administrative courts is sixty days unless a special period applies, and written notification is central to the calculation. Law No. 4054 also ties periods in Board decisions to service of the reasoned decision. Valid service, electronic notification, holidays and any special rule must be checked before entering a final date. An optional administrative application under Article 11 of Law No. 2577 can affect a running period only if its content, addressee and timing satisfy the provision; ordinary correspondence does not automatically stop the clock.

The route after a first-instance judgment depends on the court, the judgment and the current statutory appeal and cassation rules. A guide should not promise that every case follows the same sequence. Preserve the original service record, petitions, interim orders, hearing material, judgment and later notifications in one chronology. That record supports both deadline control and an accurate explanation to auditors, lenders or the parent board.

Administrative procedure rules can change independently of competition law. Before a petition is filed, the current official text of Law No. 2577 should be retrieved directly and checked together with the service record. This is particularly important when an Article 11 application, electronic service, a stay request or a later appellate route is contemplated. A dated translation or earlier consolidated copy should not be treated as conclusive.

10. Internal governance and the investigation record

The investigation team should have one verified fact base. Local management may understand the commercial events; regional teams may control systems; the parent may hold policies and board records; and outside counsel may coordinate legal positions. None should run an independent production. A decision log should identify who authorised each preservation instruction, search, translation, response, privilege position and procedural application.

Use the following controlled checklist and adapt it to the served instrument:

Authenticate the request, inspection authorisation, investigation notice or reasoned decision.
Identify the addressed entity, alleged conduct, relevant market contacts, custodians and systems.
Preserve physical and electronic material and suspend deletion without altering original evidence.
Calendar every document-specific deadline from verified service records.
Assign factual owners and independent reviewers to each information-request answer.
Maintain an inspection log, device chronology, production index and copy set.
Review privilege item by item under the Turkish defence-rights test.
Separate procedural-fine exposure from the suspected substantive infringement.
Evaluate commitments, settlement and cartel leniency as distinct procedures.
Record current-law checks for implementing rules, annual minima and transitional provisions.
Prepare judicial-review and stay analyses separately after the reasoned decision.
Keep merger notification and clearance analysis in its dedicated workstream.

The final quality check should ask whether every factual statement is supported, every deadline has a service trigger, every amount has an identified legal and accounting basis, and every procedural option carries its conditions and consequences. It should also confirm that no employee has been asked to reconstruct a record from memory when source documents exist, no data has been deleted or moved, and no foreign-law assumption has silently displaced the Turkish rule.

11. Questions about the investigation process

Six procedural questions

Can the Turkish Competition Authority investigate a company with no Turkish subsidiary?

Yes, potentially. Article 2 of Law No. 4054 covers conduct by undertakings operating in Turkish markets and conduct affecting those markets. The Authority still needs a sufficient Turkish market connection on the facts; foreign status does not create immunity, and it does not make every overseas act subject to Turkish law.

Must a company answer an information request within a standard number of days?

The controlling period is the deadline set in the served request. Verify the document, service event, scope and any extension rather than relying on a generic timetable. Responses should be reconciled to source records because late, missing, incorrect or misleading information can create revenue-based procedural exposure.

May employees delete private messages or change phones when inspectors arrive?

They should not delete, alter, hide or remotely wipe potentially responsive data after arrival. Pirelli and NAOS show how message deletion, device or SIM handling and data-integrity concerns can support an obstruction finding. The precise scope of inspection and any genuinely private or privileged material still require controlled, fact-specific handling.

Are all communications with company lawyers privileged?

No. The Board's Tatko decision uses a narrow test focused on communications with an independent lawyer that are directly connected to exercise of defence rights. In-house communications are not automatically protected under that formulation, and a lawyer's participation or privilege label is insufficient by itself. The current record and judicial authority must be checked.

Which is better: commitments, settlement or leniency?

They are different procedures, so there is no universal ranking. Commitments address eligible Article 4 or 6 concerns but exclude clear and hard infringements. Settlement involves admission during an investigation and limits review of settled matters. Active cooperation targets cartels and depends on chronology, evidence and compliance under the 2023 regulation and its transitional provisions.

Does filing a court case suspend a Competition Board decision?

No. An annulment action does not automatically stop implementation or fine collection. A separate stay request generally must show both clear unlawfulness and irreparable or impossible harm. The filing period and available review route must be calculated from valid service and the law applicable to the specific decision.

12. Official sources and publication limits

Official sources

The following official materials underpin this guide:

This guide cannot determine a company’s deadline, privilege position, fine, procedural eligibility or judicial outcome without the served documents and underlying record. The official sources and annual minimum were checked again on 5 October 2026. For the relevant matter date and again on publication day, the current official text of Law No. 2577, any replacement on-site inspection regulation or guide, the legal status of the 2020 digital-inspection guide and the official annual minimum used for procedural fines must still be verified. Those checks do not change the durable statutory percentages stated above, but they may change which text, transition or minimum applies. No result is guaranteed.

Turkish Competition Authority Investigations: Procedure, Evidence and Judicial Review