How to Respond to a TCA Investigation in Turkey (2026): Step‑by‑step for Companies

When the Turkish Competition Authority (TCA, Rekabet Kurumu) opens a formal investigation, the clock starts immediately and every procedural misstep carries significant consequences. Understanding how to respond to a TCA investigation in Turkey is essential for any company, domestic or foreign, that operates in or affects the Turkish market. The 2026 enforcement environment has intensified: the TCA has launched wide-ranging probes across health insurance, digital platforms and streaming services, while several investigations have concluded through the commitments procedure. This guide provides a complete, stepwise playbook, covering the first 72 hours through to the final decision and appeals, designed for general counsel, compliance officers and business leaders who need actionable deadlines, document checklists and practical guidance grounded in Law No.

4054 on the Protection of Competition and current TCA practice.

Overview of the TCA Investigation Process and Who It Applies To

A TCA investigation follows a structured sequence, each stage triggered by a formal act of the Authority. The typical lifecycle proceeds as follows: preliminary inquiry → decision to open a formal investigation → service of notice → first written defence → on‑site inspections (dawn raids) → investigation committee opinion → second written defence → commitments window → oral hearing → final Board decision → appeal. Not every investigation passes through every stage, some conclude early through accepted commitments, and inspections may occur at any point during the investigation.

The TCA can investigate any undertaking (company, sole trader, partnership) or association of undertakings (trade body, industry group) whose conduct affects competition in the Turkish market. This extends to corporate groups, parent companies, subsidiaries, affiliates and agents, and, critically, to foreign entities where the effects doctrine applies. Investigations may be triggered by complaints from competitors, customers or whistleblowers, by leniency applications from cartel participants, or by the TCA’s own sector monitoring and ex officio inquiries.

If your company receives a TCA investigation notice or experiences a dawn raid, the following five actions should be taken within the first 72 hours: preserve all potentially relevant evidence, notify senior management and the board, engage external competition counsel, designate a single point of contact for TCA communications, and issue an internal communications hold. Each of these is detailed in Step 1 below.

Eligibility and Prerequisites: Who the TCA Can Investigate

Any entity that qualifies as an undertaking under Law No. 4054 can be subject to a TCA investigation. This encompasses commercial companies (regardless of legal form), state‑owned enterprises operating in competitive markets, industry associations, and individuals acting in a commercial capacity. The jurisdictional reach of the TCA is broad: it extends to any conduct that produces anti‑competitive effects within Turkey, even where the entity is domiciled abroad and the agreement was executed outside Turkish territory.

Within corporate structures, the TCA regularly examines the conduct of parent companies alongside their Turkish subsidiaries. Third‑party contractors, distributors and agents may also fall within the scope of an investigation where their actions form part of the alleged infringement, for example, resale price maintenance arrangements enforced through distribution networks. It is important to note that leniency applications by one participant in a cartel can trigger an investigation that ultimately reaches other participants who had no prior notice of the inquiry.

Foreign Company Considerations

Foreign companies can be, and routinely are, investigated by the TCA where their conduct has effects on competition in Turkey. The effects doctrine means that the relevant nexus is the impact on the Turkish market, not the nationality or domicile of the undertaking. Foreign companies with Turkish subsidiaries, distributors or customers should treat a TCA notice with the same urgency as a domestic recipient. Fines are calculated on Turkish turnover, but the TCA has the power to address its decisions to foreign parent entities.

How to Respond to a TCA Investigation in Turkey: Step‑by‑Step Procedure

The following six steps form the core of any effective response to a TCA investigation. Each step identifies who is responsible, what actions are required, and the applicable deadlines. The mandatory timeline table at the end of this section consolidates these into a single reference.

Step 1: Immediate Response, First 0–72 Hours

The first 72 hours after receiving a TCA investigation notice (or experiencing a dawn raid) are the most critical. Mistakes made in this window, particularly evidence spoliation, uncoordinated statements to TCA inspectors, or inadvertent waiver of legal privilege, are extremely difficult to reverse. The following checklist should be actioned immediately:

• Identify all recipients of the notice. Determine every entity and individual within the corporate group named in or affected by the TCA’s letter.
• Issue a litigation/investigation hold. Instruct all relevant personnel to preserve documents, emails, electronic files and communications, suspend any routine deletion policies immediately.
• Isolate potential custodians. Identify the individuals whose files, devices and communications are most likely to be relevant to the allegations.
• Notify senior management and the board. Ensure the C‑suite and, where appropriate, the board of directors are informed within hours, not days.
• Preserve legal privilege. Mark all communications with external counsel as privileged and confidential. Do not circulate legal advice internally without privilege markings.
• Engage external competition counsel. Contact specialist Turkish competition law counsel immediately, before responding to any TCA request.
• Log the chain of custody. Record every document produced, seized or copied during any TCA interaction, with dates and responsible persons.
• Prepare a press and communications hold. Ensure no public statements are made without legal review. Designate a communications spokesperson if required.
• Designate a single point of contact for the TCA. All contact with the Authority should flow through one nominated individual (typically external counsel or a senior in‑house lawyer).

Step 2: Assess the Notice and Instruct Counsel, Days 1–7

Within the first week, your legal team must perform a detailed assessment of the TCA’s notice. This means reading the notice in full, identifying the specific allegations (the articles of Law No. 4054 cited, the market definition, the conduct described), and noting the investigation number assigned by the TCA. If any aspect of the notice is unclear, counsel should submit a written request for clarification to the investigation unit, this should be done promptly, as it does not extend statutory deadlines.

At this stage, decide whether to instruct external competition counsel (if not already done) and assemble the internal response team: in‑house legal, compliance, the business unit involved, IT (for document collection) and, where necessary, forensic data specialists. Begin mapping the documents and data likely to be relevant, custodial interviews with key personnel should start immediately to identify where responsive materials are held.

Step 3: Prepare and Submit the First Written Defence

The first written defence deadline is typically 30 days from service of the formal investigation notice. This is the single most important procedural deadline in the entire TCA investigation process: it is the company’s first and most substantive opportunity to set out its factual account and legal arguments before the investigation committee forms its preliminary view.

The first written defence should be structured to address every allegation in the TCA’s notice. Practically, this means including: a clear statement of facts (supported by documentary evidence), legal arguments addressing each article of Law No. 4054 cited in the notice, a complete index of evidence and appendices (contracts, pricing data, emails, internal analyses), witness statements where relevant, and confidentiality requests for any commercially sensitive material. Reference the investigation number on every page and in all correspondence.

Internal sign‑off is essential: ensure the defence is reviewed by both legal and the relevant business units before submission. File the written defence with the TCA within the 30‑day window, late submissions risk being disregarded or treated as a procedural default. Where the notice specifies a different deadline, that deadline prevails.

Step 4: Handling On‑Site Inspections and Dawn Raids

The TCA has the power to conduct on‑site inspections, commonly referred to as dawn raids, at company premises, sometimes without prior notice. These inspections can occur at any point during an investigation and are a powerful evidence‑gathering tool. Compliance is mandatory: obstructing or hindering a TCA inspection is a separate offence carrying its own penalties under Law No. 4054.

During a dawn raid, the company’s designated inspection liaison should take the following actions:

• Request the inspection order. Ask TCA inspectors to produce their written authorisation before granting access.
• Comply with all lawful requests. Produce documents, open files and provide access to electronic systems as directed.
• Protect privileged materials. If inspectors request documents covered by legal professional privilege (communications with external counsel for the purpose of legal advice), raise the privilege claim immediately and seek to set the document aside for adjudication.
• Log every item seized or copied. Maintain a contemporaneous record of all documents, devices, and electronic files taken or copied by the TCA, with timestamps.
• Request a copy of the seized items list. The company is entitled to receive a list of materials taken by the TCA, insist on receiving this before inspectors leave the premises.
• Do not destroy, alter or conceal any materials. Any attempt to obstruct the inspection will be treated as a serious aggravating factor.

Step 5: Second Written Defence, Investigation Committee Opinion, and Commitments

After the first written defence is submitted, the TCA investigation committee reviews the evidence and the company’s submissions. The investigation committee has 15 days to prepare an additional opinion concerning the second written defence. The company will then be given a further opportunity to respond, this is the second written defence, and the deadline is set by the TCA’s letter (commonly 15–30 days, though this varies by case).

At this stage, companies should also consider whether to propose commitments to the TCA. The TCA commitments procedure allows undertakings to offer behavioural or structural remedies that address the competition concerns identified by the Authority, potentially resolving the investigation without a finding of infringement or a fine. Commitment proposals must be made in writing, submitted by registered mail and email to the TCA’s investigation unit, and should include a detailed implementation plan and schedule. For a detailed walkthrough of how to propose commitments, see the guide to proposing commitments to the Turkish Competition Authority.

Step 6: Hearing, Final Decision, Enforcement, and Appeals

If the investigation is not resolved through commitments, the TCA Board will schedule an oral hearing. At the hearing, the investigated company may present its case directly to the Board members, this is the final opportunity to influence the outcome before the decision is issued. Legal counsel should prepare submissions carefully and anticipate questions on both the facts and the legal framework.

The TCA Board’s final decision may result in one of several outcomes: acceptance of commitments (terminating the investigation), a finding of no infringement, or a finding of infringement accompanied by administrative fines. Where fines are imposed, they can reach up to 10% of the undertaking’s Turkish turnover under Law No. 4054. The TCA may also impose behavioural or structural remedies.

Companies may appeal TCA final decisions to the administrative courts. The appeal must be filed within the statutory window specified in the decision, failure to appeal in time results in the decision becoming final and enforceable. Post‑decision, companies should also consider whether to apply for a stay of execution pending the appeal.

TCA Investigation Process: Timeline and Responsible Parties

Important: The deadlines above reflect common TCA practice and 2026 reporting. Always verify against the dates specified in the TCA notice for your specific case, the notice controls.

Documents Needed for a TCA Investigation

Preparing a complete and well‑organised document set is central to an effective defence. The table below lists the core documents typically required during a TCA investigation. For each, the notes column identifies who issues the document, the preferred format, and key practical considerations.

When preparing documents for production, separate privileged materials (communications with external counsel for the purpose of obtaining legal advice) from non‑privileged materials. Clearly mark privileged documents and prepare a privilege log. Commercially sensitive information should be marked as confidential and a confidentiality request submitted to the TCA alongside the production. Where electronic documents are produced, preserve metadata and maintain a record of the search methodology used.

TCA Written Defense Timeline and Key Deadlines

Deadlines in a TCA investigation are strict. Missing the first written defense deadline means the TCA may proceed on the existing record, with limited opportunity to present the company’s side of the story. The following table consolidates the key deadlines that in‑house teams must track from the moment a formal investigation notice is served.

One practical instruction applies to every row in this table: always check the dates specified in the TCA notice or decision letter for your specific case. The notice controls. Where you believe a deadline is unreasonably short given the complexity of the case, counsel should promptly request an extension in writing, though extensions are granted only in exceptional circumstances and at the TCA’s discretion.

Industry observers note that companies which build internal deadline tracking systems (integrated with legal case management software) and assign a named deadline owner for each procedural step significantly reduce the risk of missed filings. In complex, multi‑party investigations, coordinating deadlines across affiliated entities is a common challenge that warrants early attention.

Costs, Fines, and Financial Considerations

Responding to a TCA investigation carries substantial financial exposure, even before any fine is imposed. The table below summarises the main cost categories that companies should anticipate and budget for when planning their response to a TCA investigation in Turkey.

Legal fees are subject to VAT in Turkey. For multinational groups, currency exposure (Turkish Lira fluctuations) should be factored into budgeting for both fines and advisory costs. Companies should also consider the potential for follow‑on private damages claims by affected third parties if an infringement finding is made.

What Changed in 2026: Procedural Clarifications and the TCA Enforcement Uptick

The first half of 2026 has marked a significant escalation in the TCA’s enforcement activity and a number of procedural developments that directly affect how companies should respond to an investigation. The TCA launched a wide‑ranging investigation covering insurers, private healthcare providers, and service and IT providers in the health insurance sector. In parallel, digital platform and streaming service investigations have progressed rapidly, the TCA’s own announcements confirm that an investigation into Netflix, BluTV, Disney, Amazon Prime, Exxen and Gain was concluded through the commitments procedure in June 2026.

The likely practical effect of these developments for corporate legal teams is threefold. First, the pace of TCA investigations has increased: companies should expect shorter timelines for information requests and more extensive document production demands than in previous years. Second, the TCA commitments procedure has become a more frequently used resolution mechanism, early indications suggest that companies which engage proactively on commitments, particularly in digital markets, are achieving faster resolution and avoiding fines. Third, the investigation committee’s role in reviewing written defences and issuing additional opinions has been clarified through Q1 2026 enforcement bulletins, reinforcing the importance of treating every written submission as a substantive opportunity to shape the committee’s view.

What should corporate legal teams change in their internal playbooks for 2026? Industry observers expect three operational shifts: faster incident response protocols (compress the first 72 hours into 24–48 hours where possible), more detailed and earlier document mapping (start mapping before the first written defence deadline begins to run), and a readiness to engage on commitments from the outset of any investigation, rather than treating commitments as a fallback after the written defence phases have concluded.

Common Pitfalls When Responding to a TCA Investigation and How to Avoid Them

• Missing or late first written defence. This is the most consequential procedural error a company can make. If the 30‑day deadline passes without a submission, the TCA proceeds on the record. The practical effect is that the company loses its first, and most impactful, opportunity to present its account and legal arguments. Mitigation: assign a named deadline owner the moment the notice arrives; build in at least five days’ buffer before the filing date.
• Producing privileged materials without marking privilege. Once privileged communications are disclosed to the TCA without a privilege claim, recovering them is extremely difficult. Mitigation: implement a privilege review stage in every document production workflow; train custodians not to forward legal advice without privilege markings.
• Obstructing an on‑site inspection. Any attempt to delay, hinder or obstruct a TCA dawn raid, including destroying documents, refusing access, or providing misleading information about the location of files, constitutes a separate offence under Law No. 4054 and may attract additional fines. Mitigation: conduct annual dawn‑raid readiness training for reception staff, IT teams and senior management.
• Providing false or misleading information to the TCA. Under Law No. 4054, supplying incorrect, incomplete or misleading information to the TCA, whether in written submissions, during inspections or in response to information requests, is independently sanctionable. Fines for misleading information are imposed separately from fines for the substantive infringement. Mitigation: all factual statements in TCA submissions should be verified by the individuals with direct knowledge; implement a sign‑off procedure that requires business unit heads to confirm accuracy.
• Failing to propose commitments when they are advisable. The commitments procedure can resolve an investigation without a finding of infringement or a fine. Companies that wait too long to engage on commitments may find that the TCA’s appetite for a negotiated resolution has diminished. Mitigation: assess the merits of a commitments approach in the first week of the investigation and discuss it with counsel as a live option throughout.
• Inadequate internal record‑keeping and data preservation. Routine data deletion policies that destroy responsive documents after the investigation has commenced can be treated as evidence of obstruction. Mitigation: issue a litigation hold immediately upon receipt of notice and audit compliance with the hold at regular intervals.

Sources

1. Turkish Competition Authority (Rekabet Kurumu), Hot News / Announcements
2. Turkish Competition Authority (Rekabet Kurumu), Main Site
3. Resmi Gazete (Turkish Official Gazette), Law No. 4054 on the Protection of Competition
4. International Competition Network (ICN), CAP Template: Turkey