Abuse of Dominance in Turkey (2026): What Dominant Firms, Competitors and In‑house Counsel Need to Know

Abuse of dominance Turkey enforcement has entered a decisive new phase in 2026, with the Turkish Competition Authority (Rekabet Kurumu, the TCA) sharpening its focus on market‑structure analysis and procedural enforcement. This shift raises the stakes for dominant firms, their competitors and the in‑house teams advising them. The old assumption, that a strong market position alone is harmless, no longer holds where conduct forecloses rivals or exploits counterparties. This guide gives practitioners a decision‑grade framework: the legal test, investigation triggers, evidence strategy, remedies, a step‑by‑step defence timeline and a compliance checklist.

Legal test, What counts as abuse of dominance under Turkish law?

Abuse of dominance in Turkey is governed by Law No. 4054 on the Protection of Competition, principally Article 6. The statute does not prohibit dominance itself. It prohibits the abuse of a dominant position. Competition Board decisional practice applies a consistent three‑part analysis: (1) the undertaking holds a dominant position in a properly defined relevant market; (2) its conduct amounts to an abuse; and (3) that conduct restricts, or is capable of restricting, competition or exploits trading partners.

Each element must be established on the evidence. A TCA abuse of dominance case therefore stands or falls on market definition, proof of market power, and a careful characterisation of the conduct. Intent is not a precondition, the Board examines the effects, or likely effects, of the behaviour. Where conduct has an objective business justification or produces pro‑competitive efficiencies that outweigh any foreclosure, that is a defence that the undertaking may raise.

Dominant position, definition and market share guidance

Under Law No. 4054, a dominant position is defined as the power of one or more undertakings to determine economic parameters such as price, supply, output and distribution in a particular market, independently of competitors and customers. Market share is the starting proxy, not the conclusion.

• High shares. A sustained share well above rivals creates a strong indication of dominance, particularly where the gap is durable.
• Mid‑range shares. Shares in a contested band require corroborating factors, entry barriers, buyer power, capacity constraints, network effects or control of essential infrastructure.
• Dynamic markets. In fast‑moving or platform markets, the TCA increasingly weighs structural features such as data advantages and gatekeeper positions alongside static share figures.

In 2026 the Authority’s emphasis on market‑structure analysis means dominance findings are being built on a richer evidentiary record, margins, entry conditions and the durability of market power, not headline percentages alone.

Abuse types, exclusionary versus exploitative conduct

TCA abuse of dominance practice divides abusive conduct into two broad families:

• Exclusionary conduct. Behaviour that forecloses rivals, refusal to supply, margin squeeze, loyalty rebates, tying, bundling and exclusive dealing. The test asks whether the conduct is capable of foreclosing an as‑efficient competitor.
• Exploitative conduct. Behaviour that extracts value directly from counterparties, excessive or discriminatory pricing and unfair trading terms. The test focuses on whether terms depart from those achievable under competitive conditions.

Both families are capable of attracting the full sanctioning framework of Law No. 4054. Exclusionary cases dominate enforcement, but exploitative theories, especially excessive pricing, have gained traction in sectors with limited competitive pressure.

When will the TCA open an abuse of dominance investigation?

A dominance investigation in Turkey can begin in several ways, and understanding the triggers is the first line of risk management. The TCA is not purely reactive. Its 2026 posture gives significantly more weight to proactive market monitoring as an early‑warning mechanism.

• Complaints. Competitors, customers or suppliers file complaints alleging foreclosure or exploitation. A credible complaint with supporting documents frequently triggers a preliminary inquiry.
• Ex officio action. The Authority opens cases on its own initiative, often following a sector inquiry or market study that flags structural concerns.
• Market studies. The TCA’s 2026 emphasis on market‑structure scrutiny means sector studies can function as a pipeline into targeted enforcement. Firms named or implicated in a study should treat it as an advance signal.
• Dawn raids. Where preliminary evidence exists, inspectors can arrive unannounced to gather documents and electronic data.

Formal investigation versus preliminary inquiry

The process typically runs in stages. A preliminary inquiry is an initial assessment of whether there is sufficient basis to proceed. If the Board decides the threshold is met, it opens a formal investigation. The distinction matters: a formal investigation carries procedural rights, structured deadlines and the eventual delivery of an investigation report and objections to which the undertaking must respond.

Statutory timelines, suspension and interim measures

Formal investigations in a TCA abuse of dominance matter proceed through defined phases, investigation, written defences, oral hearing where requested, and final decision, within the timeframes set under Law No. 4054. The Authority can also impose interim measures where there is a risk of serious and irreparable harm to competition before the case concludes. Respondents should assume that aggressive conduct can be frozen early, and plan contingency operations accordingly.

Market definition and evidence, how to build or rebut the TCA market

Market definition is the battleground on which most abuse of dominance Turkey cases are won or lost. Define the market too narrowly and dominance becomes almost automatic; define it correctly and the whole theory of harm may collapse. Both the Authority and respondents invest heavily in this analysis, drawing on methodology aligned with international practice.

A central tool is the SSNIP test (Small but Significant Non‑transitory Increase in Price), which asks whether a hypothetical monopolist could profitably raise prices by a small but significant amount without customers switching away. If customers would switch to other products (demand substitution) or other suppliers would quickly begin producing the product (supply substitution), those alternatives belong in the same market.

Quantitative evidence, market shares, prices, margins, elasticities

Numbers anchor market definition and the dominance assessment. A credible evidentiary record should assemble:

• Market share data over several years, by volume and value, with a transparent methodology.
• Pricing series showing how prices moved relative to rivals and across geographies.
• Margin analysis to test for excessive pricing or margin squeeze.
• Demand elasticities and switching data demonstrating how customers actually respond to price changes.

Qualitative evidence, contracts, distribution and switching costs

Economics alone rarely decides a case. Qualitative material frames how the market really functions:

• Contracts and distribution agreements revealing exclusivity, rebate structures or tying arrangements.
• Customer and competitor testimony on real substitution behaviour and barriers to switching.
• Internal documents, strategy papers, board minutes and emails, which the TCA reads closely for evidence of foreclosure intent or market power.

Practical tips for eDiscovery and data preservation

Internal documents cut both ways. A single careless email describing a plan to “shut out” a rival can undermine an otherwise defensible position. Dominant firms should implement disciplined data governance, apply legal holds the moment an investigation is foreseeable, and ensure electronic data, including messaging platforms, is preserved intact. In a dominance investigation in Turkey, the authenticity and completeness of preserved data materially affect credibility before the Board.

Common exclusionary conducts and case examples

Exclusionary conduct Turkey enforcement concentrates on a recognisable set of practices. Each has its own legal test, typical evidence and available defences. The fact patterns below are generic illustrations of conduct types, not attributions to any specific undertaking.

Refusal to supply, test and defences

Refusal to supply cases arise where a dominant firm declines to deal with a customer or competitor, or withdraws an existing supply relationship. The conduct may become abusive where the input is indispensable, the refusal is likely to eliminate effective competition downstream, and there is no objective justification.

Illustrative pattern: a dominant supplier of a key component terminates deliveries to an independent downstream rival shortly after launching its own competing downstream product. The timing and absence of commercial rationale invite scrutiny.

• Defences: objective justification (creditworthiness, capacity limits, technical incompatibility), the existence of realistic alternative inputs, and evidence that the counterparty could self‑supply or source elsewhere.

Loyalty rebates and margin squeeze

Loyalty rebates reward customers for concentrating purchases with the dominant firm, potentially foreclosing rivals who cannot match the conditional discount. Margin squeeze occurs where a vertically integrated dominant firm sets the gap between its upstream input price and downstream retail price so narrow that an as‑efficient competitor cannot profitably operate.

• Defences: rebates tied to genuine cost savings or volume efficiencies; an as‑efficient‑competitor analysis showing no foreclosure; pricing above relevant cost benchmarks.

Tying, bundling and foreclosure

Tying conditions the sale of one product on purchase of another; bundling packages products together. Both can leverage dominance in one market into an adjacent one. The Board examines whether the tying and tied products are separate, whether customers are coerced, and whether competition in the tied market is foreclosed.

Illustrative pattern: a dominant firm makes access to its essential platform conditional on also taking a secondary service, squeezing out independent providers of that service.

• Defences: technical or safety integration, genuine customer demand for the bundle, and clear availability of unbundled alternatives.

Remedies, fines and enforcement trends (2026)

When the Competition Board finds an abuse of dominance, its toolkit spans monetary and non‑monetary measures. The 2026 enforcement trend is unmistakable: greater willingness to probe market structure, more frequent use of market studies as a precursor to action, and a readiness to pair fines with durable remedies rather than relying on penalties alone.

Administrative fines are calculated under Law No. 4054 and the related Regulation on Fines, and are linked to the undertaking’s annual gross revenue, subject to aggravating and mitigating factors and to the maximum rate set out in the legislation. Final decisions, including fines and remedies, are published on the TCA’s website and relevant decisions are announced in line with the Authority’s publication practice, which triggers enforcement and collection procedures. The Board may also accept commitments, binding undertakings offered by the parties to resolve concerns before a contested decision, and operate a settlement procedure introduced into Turkish competition law.

Interim measures and emergency relief

Where there is a credible risk of serious and irreparable harm before the investigation concludes, the Board can order interim measures to halt the conduct. For respondents, this is a critical pressure point: a measure can disrupt commercial operations months before any finding of liability, making early engagement essential.

Commitments versus contested remedies

Commitments offer speed and certainty but are binding and public; breach exposes the undertaking to further Board action. Contested remedies, behavioural or structural, are imposed by the Board after a full decision and can be appealed. The choice between offering commitments and contesting the case shapes cost, timing and reputational exposure.

Appealability and enforcement of remedies

Behavioural and structural remedies, and the fines that accompany them, are enforceable once the decision takes effect. Appeals to the competent administrative courts are available, but whether an appeal suspends enforcement (a stay of execution) is a decisive planning question determined by the court on the facts. Counsel must coordinate Board strategy and court strategy from the outset.

Comparison: Behavioural vs Structural Remedies vs Fines vs Commitments, practical decision grid

Decision framework, remedies, settlement or litigation

Choose behavioural remedies when:

• The harmful conduct is discrete, separately definable and supervisable, a specific contract term or rebate scheme, and divestiture would not cure the market.
• You want to preserve the business model with limited operational disruption.
• Speed and lower immediate cost matter, and monitoring is acceptable.

Choose structural remedies when:

• Dominance is rooted in durable structural factors, gatekeeper infrastructure or merged market shares, and behavioural rules would be easily circumvented.
• The organisation accepts substantial reorganisation to remove the anticompetitive incentive.
• There is regulatory appetite for durable market correction.

Choose settlement/commitments when:

• The evidence is mixed but there is a realistic path to narrow commitments that fully address the Board’s concerns.
• You prioritise certainty, faster resolution and reputational management.

Choose litigation when:

• Strong legal or factual defences exist, objective justification, pro‑competitive efficiencies, or effects that outweigh foreclosure.
• You can withstand a longer, precedent‑setting process, interim measures and reputational exposure.

In short, let four variables drive the decision: the strength of your evidence, the structural source of market power, your tolerance for business disruption, and whether you value speed over finality. Where evidence is strong and the theory of harm fragile, litigate. Where evidence is mixed and disruption intolerable, settle. Where the market itself is the problem, expect structural pressure.

How to respond if accused of abuse of dominance in Turkey, defence strategies and timeline

Knowing how to defend a TCA investigation begins long before the investigation report and objections arrive. The procedural timeline is largely predictable, and each phase carries distinct tasks and risks.

Immediate actions on a dawn raid and document preservation

• Activate the raid protocol. Notify in‑house and external counsel immediately; counsel should attend or join remotely without delay.
• Preserve, do not destroy. Apply legal holds instantly. Deleting, concealing or altering documents during an inspection is treated very seriously and can itself attract significant fines.
• Control the scope. Record what inspectors take, raise privilege where applicable, and keep a parallel copy where permitted.
• Limit internal disclosure. Contain knowledge of the matter to a defined team to protect the defence and prevent uncoordinated statements.

Designing the defence strategy, settlement, commitments or litigate

Once the dust settles, build the factual record independently. Prepare an internal chronology, identify the strongest objective justifications, and commission economic analysis on market definition and foreclosure effects. Decide early, using the decision framework above, whether your realistic objective is a finding of no infringement through litigation, mitigation through commitments or settlement, or containment through behavioural remedies. A defence that drifts without a strategic objective loses credibility with the Board.

Litigation and appeal routes, administrative courts

Final Board decisions in an abuse of dominance Turkey matter are subject to judicial review before the competent administrative courts, with further recourse available through the administrative appellate system. The central strategic question is whether filing an appeal secures a stay of enforcement of fines and remedies, or whether they bite immediately. Counsel should prepare the appeal thesis in parallel with the Board defence, so that litigation is a planned continuation rather than a scramble after an adverse decision.

Compliance and risk mitigation for dominant firms

Prevention is far cheaper than defence. Dominant firms should embed competition compliance into day‑to‑day commercial decisions, not treat it as an annual training formality. A credible programme also demonstrates good faith if an investigation does arise.

Ten‑point compliance checklist:

1. Maintain an up‑to‑date map of markets where the firm may be dominant.
2. Adopt a written refusal‑to‑supply protocol requiring documented justification for any termination or refusal.
3. Vet pricing and rebate schemes against foreclosure and margin‑squeeze risk before launch.
4. Review distribution and exclusivity clauses for tying and foreclosure effects.
5. Build objective‑justification files for any conduct that excludes or disadvantages rivals.
6. Train commercial teams on competition language, ban “crush the competition” rhetoric in documents.
7. Establish a legal escalation trigger for high‑risk commercial decisions.
8. Rehearse a dawn‑raid response plan and keep it current.
9. Implement disciplined data retention and legal‑hold procedures.
10. Monitor TCA market studies affecting your sector and respond proactively.

Monitoring and competition risk KPIs

Translate compliance into measurable indicators: the proportion of high‑risk contracts legally reviewed, the number of pricing schemes assessed before launch, training completion rates among commercial staff, and the time taken to apply legal holds. KPIs convert abstract risk into something the board can oversee.

Remediation after a TCA market study

If a market study identifies your sector or firm, treat it as an opportunity to self‑correct. Review flagged conduct, consider voluntary adjustments, and document the rationale. Early, visible remediation can shape the Authority’s posture and may reduce exposure if formal proceedings follow.

Conclusion

Abuse of dominance Turkey enforcement in 2026 rewards firms that prepare and penalises those that improvise. The TCA’s turn toward market‑structure analysis means dominance findings now rest on deeper economic records, and remedies increasingly aim at durable correction rather than one‑off penalties. For dominant firms, the message is to audit conduct, document justifications and rehearse a response plan before the knock on the door. For competitors and responding counsel, the opportunity lies in rigorous market definition and early strategic clarity on whether to litigate, commit or settle. Treated proactively, abuse of dominance risk becomes a managed variable rather than an existential threat.

For further reading, see our related guides on defending an abuse of dominance investigation in Turkey, market definition and evidence for TCA cases, and behavioural versus structural remedies following a TCA decision.

Sources

1. Turkish Competition Authority (TCA)
2. Law No. 4054 on the Protection of Competition (via mevzuat.gov.tr)
3. Turkish Official Gazette
4. OECD, Competition
5. European Commission, Competition
6. Union of Turkish Bar Associations (Türkiye Barolar Birliği)