Online Marketplace Advertising Rules in Turkey

Introduction

Online marketplaces have become one of the most important commercial environments in Turkey. Consumers now compare products, evaluate sellers, read reviews, ask questions, use discount coupons, see sponsored listings, receive targeted recommendations and complete purchases through digital platforms. As a result, online marketplaces are not merely sales channels; they are also powerful advertising ecosystems.

The subject of online marketplace advertising rules in Turkey is highly important for marketplace operators, electronic commerce intermediary service providers, sellers, brands, advertising agencies, influencers and foreign companies targeting Turkish consumers. A product listing, sponsored ranking, “best seller” badge, crossed-out price, discount label, consumer review, seller reply, Q&A section, marketplace campaign banner or personalized recommendation may all influence consumer purchasing decisions. Therefore, these elements may be assessed under Turkish advertising law and unfair commercial practices rules.

The main legal framework is based on Law No. 6502 on the Protection of Consumers, the Regulation on Commercial Advertising and Unfair Commercial Practices, distance sales rules, electronic commerce legislation, KVKK data protection rules and Advertising Board decisions. The Turkish Ministry of Trade states that the Advertising Board supervises commercial advertisements and unfair commercial practices directed directly or indirectly at consumers in any medium.

The regulatory environment is especially important in 2026. The Ministry of Trade announced that amendments to the Regulation on Commercial Advertising and Unfair Commercial Practices were published in the Official Gazette on 1 July 2026 to strengthen consumer protection against misleading advertising in digitalized markets. These amendments introduce rules on targeted advertising, influencer promotions, discount advertising, AI-generated advertisements, environmental claims and consumer reviews; they are scheduled to enter into force on 1 August 2026.

This article explains the main advertising rules for online marketplaces in Turkey, including product listing accuracy, seller responsibility, sponsored search results, discount advertising, consumer review verification, marketplace Q&A sections, targeted advertising, AI-generated content, dark patterns, distance sales consistency and Advertising Board sanctions.

What Is Online Marketplace Advertising?

Online marketplace advertising refers to any commercial communication displayed on or through an online marketplace to promote a product, service, seller, brand, campaign or commercial advantage. It includes traditional ad spaces such as banners and sponsored ads, but it also includes marketplace-specific features that shape consumer decisions.

Examples include product titles, product descriptions, images, seller badges, “recommended product” labels, sponsored search results, category rankings, “best seller” tags, marketplace campaign pages, discount coupons, crossed-out prices, delivery promises, product comparison tools, consumer ratings, verified purchase comments, seller Q&A replies and personalized product recommendations.

A marketplace advertisement does not need to be called an “advertisement” by the platform to fall within advertising law. If a commercial message influences consumer economic behavior, it may be reviewed as an advertisement or unfair commercial practice. The decisive issue is not the technical format, but the commercial effect and consumer perception.

For example, a seller’s product description saying “clinically proven,” “original product,” “lowest price,” “eco-friendly,” “doctor recommended,” or “guaranteed result” may create legal responsibility if the claim is misleading or unsupported. Similarly, a marketplace’s “recommended” label may be risky if the recommendation is actually based on paid placement and this is not clearly disclosed.

Legal Framework for Online Marketplace Advertising

Online marketplace advertising in Turkey is governed by several legal layers. First, general advertising law requires commercial advertisements to be accurate, honest, transparent and not misleading. Second, unfair commercial practices rules prohibit practices that distort or are likely to distort consumers’ economic behavior. Third, distance sales legislation imposes pre-contractual information obligations and requires consistency between marketplace advertising promises and mandatory pre-information. Fourth, KVKK rules apply where personal data is used for targeted advertising, profiling, cookies or marketing communication.

The Ministry of Trade’s price advertising guide is also highly relevant to marketplaces. The guide was prepared under Law No. 6502 and the Regulation on Commercial Advertising and Unfair Commercial Practices, and it expressly covers advertisers, agencies, media organizations, sellers, providers and intermediary service providers. It aims to clarify responsibilities in price information and discount advertising.

The Ministry’s distance sales guidance is particularly important for marketplace operators. It states that intermediary service providers are jointly responsible with sellers or providers for providing, confirming and proving pre-information. It also states that where data entry is made by the intermediary, the intermediary is responsible for deficiencies in mandatory pre-information and for consistency between information promised in platform advertisements/promotions and mandatory pre-information.

Therefore, marketplace advertising compliance cannot be separated from platform design, seller onboarding, product information systems, campaign tools, review systems and distance sales workflows.

Responsibility of Marketplace Operators

Marketplace operators often argue that sellers are responsible for product claims because sellers create listings. However, marketplace operators may still have legal exposure depending on their role in the advertising process.

A platform may contribute to advertising in many ways. It may design product page templates, provide discount tools, calculate crossed-out prices, promote seller products in marketplace campaigns, display sponsored rankings, create “recommended” labels, send campaign notifications, operate review systems, manage Q&A sections and control checkout design. These platform-controlled elements can affect consumer perception.

For example, if a marketplace allows sellers to enter arbitrary previous prices and automatically displays large discount percentages, the platform may contribute to misleading discount advertising. If it shows a product as “sponsored” only in a barely visible way, consumers may misunderstand the ranking. If it imports reviews from sources where purchase verification is impossible, the marketplace may mislead consumers about review authenticity.

A legally safer marketplace model requires active compliance systems. These include seller content policies, claim filters, price history controls, review verification, sponsored listing labels, clear campaign rules, category-specific advertising restrictions and prompt takedown mechanisms.

Seller Responsibility in Marketplace Advertising

Sellers remain responsible for the accuracy of their own product claims. A seller should not assume that listing a product on a marketplace shifts all responsibility to the platform. The seller’s product title, description, photos, videos, claims, seller replies, discount rates, product tags and review practices may create direct advertising law risk.

Sellers should be able to substantiate all objective claims. If a listing says “100% original,” “certified organic,” “lowest price,” “medical effect,” “clinically tested,” “eco-friendly,” or “best quality,” the seller should have evidence before publication. The seller should also ensure that product images reflect the actual product and package content. Accessories, colors, size, quantity, delivery conditions and warranty information must not be misleading.

Seller replies in Q&A sections also matter. A seller cannot make unlawful claims informally in response to consumer questions. A statement such as “this product cures eczema,” “this supplement prevents flu,” or “this device eliminates pain” may be treated as a commercial claim even if it appears in an answer section rather than the main description.

Product Listing Accuracy

Product listings are the heart of online marketplace advertising. Consumers rely on listings to understand what they are buying. Any misleading statement, omission or visual exaggeration may affect purchasing decisions.

A compliant product listing should accurately disclose the product’s identity, essential features, size, quantity, material, model, compatibility, origin, warranty, delivery conditions and limitations. If the product is refurbished, second-hand, renewed, imported, outlet, sample-size, subscription-based, digital or personalized, this should be clear.

Product visuals must also be accurate. A listing may be misleading if it shows a larger package than the actual product, includes accessories that are not sold with the product, uses digitally enhanced results, or displays a premium version while selling a basic version.

Marketplace operators should pay special attention to high-risk categories. Food supplements, cosmetics, children’s products, electronics, medical-looking devices, environmental products and financial services require stricter review because consumers may rely heavily on product claims.

Sponsored Listings and Paid Rankings

Sponsored listings are common in online marketplaces. Sellers may pay to appear higher in search results, category pages or recommendation modules. Paid placement is not unlawful by itself. The legal risk arises when consumers cannot clearly distinguish sponsored results from organic results.

A consumer may assume that top-ranked products are shown because of relevance, quality, popularity, price, seller performance or customer rating. If payment affects ranking, the marketplace should disclose this clearly. A vague or hidden label may not be enough. The disclosure should be visible, understandable and placed near the sponsored product.

Labels such as “sponsored,” “advertisement,” “promoted,” or clear Turkish equivalents should be used consistently. The same standard should apply on desktop, mobile web and mobile apps. Sponsored labels should not disappear in smaller screen layouts.

Paid ranking becomes especially risky if the platform uses trust-building wording such as “recommended,” “best choice,” “top pick,” or “customer favorite.” If the placement is paid, these labels may mislead consumers unless the commercial nature is clear.

Discount Advertising on Marketplaces

Discount advertising is one of the most common marketplace practices. Marketplaces frequently use campaign pages, crossed-out prices, coupon codes, basket discounts, member prices, flash sales, countdown timers and “limited stock” warnings. These tools are commercially effective, but they also create serious legal risk.

The Ministry of Trade announced in 2026 that conditional sales advertisements providing discounts or other benefits will be subject to discount advertising rules. It also stated that, in discount advertisements, the lowest price applied within the last ten days before the discount start date may be presented as the pre-discount price; for perishable goods such as fruit and vegetables and for services, the price immediately before the discounted price will be taken as the basis.

This rule is directly relevant to marketplaces because sellers may frequently change prices. Platforms should not allow sellers to create fake discounts by increasing prices before campaigns. A crossed-out price should reflect a genuine reference price. Discount percentages should be calculated accurately.

Marketplace operators should keep price history records and require sellers to substantiate discount claims. Sellers should avoid using “up to 80% off” if only a small number of products have that discount. Campaign conditions, start and end dates, product exclusions, stock limitations, minimum basket amounts and payment-method restrictions should be clearly disclosed.

Loyalty Programs and Member-Only Prices

Many marketplaces use membership prices, loyalty points, coupons, subscription-based discounts and app-exclusive offers. These practices may be lawful if transparent, but they may mislead consumers if they create a false discount perception.

The Ministry of Trade has stated that loyalty programs, discount cards, coupons and point systems can distort consumers’ price perception when they are used to create a false impression of discount. The Advertising Board’s principle decision provides that advertisements for goods or services offered through loyalty programs should not directly or indirectly create a discount impression through expressions such as “discount,” “saving,” “special opportunity for cardholders/members,” “pre-discount price,” crossed-out prices or downward trend graphics.

For online marketplaces, this means member prices should be presented carefully. If a member price is a permanent pricing model rather than a genuine temporary discount, the platform should not display it like a discount campaign. The difference between ordinary price, member price, coupon price and campaign price must be understandable.

Hidden Fees and Checkout Design

A marketplace listing may show a low price, but the final payable amount may increase through delivery fees, service charges, installation fees, packaging costs, insurance, payment fees or platform commissions. If mandatory costs are hidden until the final checkout step, the consumer may be misled.

A transparent marketplace should disclose mandatory costs before the consumer makes a purchasing decision. Delivery fees, minimum basket amounts, service charges and compulsory add-ons should not be hidden behind small print or revealed only after the consumer has invested time in the purchase flow.

The Ministry of Trade’s distance sales guidance also emphasizes that if sellers do not properly inform consumers about additional costs, consumers may not be obliged to pay them. It further states that the consumer must be clearly informed immediately before order approval that the order creates a payment obligation.

This means checkout design is not only a technical issue. It is also a consumer protection issue. Button wording, fee visibility, pre-selected add-ons and final price presentation should be reviewed legally.

Consumer Reviews and Ratings

Consumer reviews are among the most influential marketplace advertising tools. A product with many positive reviews and high ratings may appear more trustworthy than a product without reviews. For this reason, review systems must be authentic and transparent.

The 2026 amendments introduced important rules on consumer evaluations. According to the Ministry of Trade, consumer reviews obtained from platforms where purchase verification is not possible may not be published. In addition, if reviews are categorized under headings such as product, service, delivery, seller or provider, all such evaluations must be displayed in the same area in a clear, understandable, distinguishable and easily accessible way.

Marketplace operators should therefore build review systems around verified purchases. They should prevent fake reviews, review farms, AI-generated reviews, employee reviews disguised as consumer comments, review hijacking and selective suppression of negative comments. Incentivized reviews should be transparent and should not reward only positive ratings.

A seller should not be allowed to transfer reviews from one product to another unrelated product. A high rating for an old product version should not mislead consumers about a materially different new version. The platform should also make delivery, seller service and product quality reviews separately visible where relevant.

Q&A Sections and Public Seller Replies

Marketplace Q&A sections are often overlooked, but they can be legally significant. Consumers ask questions about product use, quality, health effects, compatibility, delivery, warranty and performance. Seller replies may influence not only the person asking the question but also future consumers who read the answer.

The Advertising Board has already focused on misleading health claims in marketplace Q&A areas. In 2026, the Ministry of Trade announced that sellers frequently used electronic marketplace Q&A sections for misleading health claims, including disease-treatment expressions, and that sanctions were imposed on nine firms in relation to such practices.

This enforcement trend shows that marketplaces should monitor Q&A sections, not only product descriptions. High-risk words such as “cures,” “treats,” “prevents disease,” “doctor recommended,” “no side effects,” “guaranteed result,” “medical,” “detox,” “slimming,” and “pain relief” should trigger review in relevant categories.

Sellers should be trained that public answers are commercial communications. A casual reply can become an unlawful advertisement.

Targeted Advertising and Personal Data

Online marketplaces use targeted advertising extensively. They may recommend products based on browsing history, previous purchases, abandoned carts, location, search terms, app behavior, demographic segments or consumer profiles. Such practices can increase conversion, but they raise advertising law and KVKK issues.

The 2026 amendments introduced transparency rules for targeted advertising. The Ministry of Trade stated that advertisers may use targeted advertising if they provide consumers with direct and easily accessible information about the criteria used to show the advertisement and how those criteria can be changed. The same amendments prohibit targeted advertising directed at children through profiling based on personal data.

For marketplaces, this means personalized recommendations, retargeting ads, segmented discounts and behavioral campaign banners should be reviewed. Consumers should be able to understand why they are seeing certain ads or offers and how they can change relevant criteria.

If cookies, pixels, SDKs or third-party advertising networks are used, KVKK compliance should also be assessed. Privacy notices, explicit consent mechanisms, cookie preferences and data sharing arrangements must align with the advertising model.

Influencer-Linked Marketplace Advertising

Many online marketplaces work with influencers through storefronts, affiliate links, discount codes and curated product pages. These tools can generate sales, but they also create disclosure obligations.

The 2026 amendments state that where social media influencers obtain a benefit such as earnings, discounted products or services, or event participation, their posts must clearly indicate the advertising nature through expressions such as “advertisement” or “promotion.”

A marketplace should therefore ensure that influencer storefronts and affiliate links disclose the commercial relationship. If an influencer receives commission when consumers buy through a link or code, the consumer should understand this before purchasing.

Influencer product claims should also be controlled. An influencer should not make unauthorized health claims, false price claims, fake personal experience statements or unsupported superiority claims. If the marketplace reposts influencer content, uses it in paid ads or displays it on product pages, the marketplace should also review compliance.

AI-Generated Marketplace Content

AI-generated content is increasingly used in product descriptions, images, virtual models, customer service replies, review summaries and recommendation systems. AI may improve marketplace efficiency, but it may also create misleading advertising risks.

The 2026 amendments require clear disclosure where advertisements use AI-generated digital characters that cannot be distinguished from real humans. They also prohibit advertisements where an AI-generated digital copy of a real person creates the impression that the person personally experienced or recommended a product or service.

Marketplaces should avoid using AI to create fake consumer reviews, synthetic testimonials, unrealistic before-and-after images or virtual endorsers that appear to be real users. AI-generated product descriptions should be checked for accuracy. Automated seller tools should not generate prohibited health, environmental or superiority claims.

Environmental Claims in Marketplace Listings

Environmental claims are increasingly common on marketplaces. Sellers use terms such as “eco-friendly,” “sustainable,” “green,” “recyclable,” “biodegradable,” “carbon neutral,” “natural,” or “climate friendly.” These claims may strongly influence consumers but can also create greenwashing risk.

The 2026 amendments prohibit broad environmental expressions such as “environmentally friendly” without explanation. They also require environmental claims to specify the relevant stage of the product or service life cycle and require certificates or approvals to be substantiated by documents from competent institutions, universities, accredited bodies or independent testing and evaluation organizations.

Marketplace operators should therefore require evidence for environmental badges and claims. Sellers should not use green icons, leaf symbols or sustainability tags unless the environmental claim is specific, clear and documented.

Food Supplements, Cosmetics and Health Claims

Online marketplaces frequently sell food supplements, cosmetics, herbal products, wellness products and medical-looking devices. These categories require strict advertising review because consumers may rely on claims affecting health, appearance or bodily integrity.

The 2026 amendments prohibit food supplement advertisements that create the impression that supplements replace foods consumed as part of normal nutrition. The amendments also allow comparative advertising for food supplements except for matters falling within the scope of health claims.

Marketplace listings should not present food supplements as medicines. Sellers should avoid disease-treatment claims, exaggerated immunity claims, “doctor approved” expressions and consumer testimonials implying cure or prevention. Cosmetic products should not be promoted as treating diseases. Product reviews and Q&A answers should also be monitored because health claims may appear outside the main listing.

Dark Patterns in Online Marketplaces

Dark patterns are manipulative interface designs that push consumers toward decisions they might not otherwise make. They are common in online commerce and may include false countdown timers, fake stock warnings, pre-selected paid add-ons, hard-to-find cancellation buttons, confusing cookie banners, hidden rejection options and misleading subscription flows.

The Ministry of Trade has described dark commercial designs as online interface practices that significantly distort consumers’ economic behavior by directing them toward choices that prevent rational decision-making. It has also stated that the Advertising Board applies administrative sanctions against firms that use such designs.

Marketplaces should review not only their product content but also their interface design. The path from product discovery to checkout should not manipulate consumers. Add-ons should not be pre-selected in a deceptive way. Cancellation and return processes should not be deliberately confusing. Scarcity messages should reflect real stock conditions.

Advertising Board Sanctions

The Advertising Board may impose significant sanctions for unlawful marketplace advertising. These may include suspension of advertisements, correction, administrative fines, temporary suspension and access blocking in online environments.

For 2026, the Ministry of Trade announced that administrative fines for misleading advertisements and unfair commercial practices may range from 99,339 TL to 39,916,524 TL, depending on factors such as the unfairness of the violation, benefit obtained, harm caused, fault, economic situation of the violator and advertising medium.

The same announcement states that failure to comply with certain distance sales obligations may lead to administrative fines per unlawful transaction or contract, and that intermediary service providers may face a significant administrative fine if they fail to establish and keep continuously open systems allowing consumers to submit and track requests and notifications.

For online marketplaces, this means legal risk is not limited to a single product listing. A platform-wide design, campaign system, review structure or seller tool can create large-scale exposure.

Practical Compliance Checklist for Online Marketplaces

Online marketplaces operating in Turkey should apply a structured compliance checklist before publishing or enabling advertising content.

Product listings should be accurate, complete and supported by evidence.

Sponsored results and paid rankings should be clearly labeled.

Previous prices and discount rates should be based on verifiable price history.

Conditional discounts, coupons and member prices should be transparent.

Mandatory fees should be shown before checkout.

Pre-selected paid add-ons should be avoided.

Consumer reviews should be linked to verified purchases where possible.

Reviews from unverifiable purchase platforms should not be published.

Review categories should be displayed clearly in the same area.

Q&A sections and seller replies should be monitored.

Health, food supplement, cosmetic and environmental claims should be filtered.

Influencer storefronts and affiliate links should disclose commercial relationships.

Targeted advertising criteria should be directly and easily accessible to consumers.

Profiling-based targeted advertising directed at children should be prohibited.

AI-generated endorsements, reviews and digital characters should be reviewed.

Dark patterns should be removed from checkout, subscription, return and cancellation flows.

Advertising promises should match distance sales pre-information.

Records of claims, prices, reviews, seller communications and campaign approvals should be preserved.

Best Practices for Marketplace Sellers

Marketplace sellers should adopt their own compliance process. They should not rely solely on the platform. Every seller should review product descriptions, photos, claims, Q&A replies, price history, discount labels, customer review use and delivery promises.

High-risk claims should be avoided unless legally permitted and documented. Sellers should not make medical, environmental, “lowest price,” “best quality,” “guaranteed result,” or “certified” claims without evidence. Sellers should also avoid manipulating reviews, creating fake discounts or using misleading product tags.

Where a seller works with influencers, discount code partners or affiliate marketers, the commercial relationship must be clearly disclosed and all claims must be approved.

Conclusion

Online marketplace advertising rules in Turkey are becoming increasingly important because marketplaces are now central to consumer purchasing decisions. Product listings, sponsored rankings, discount labels, reviews, Q&A sections, influencer links, personalized recommendations and checkout designs all function as advertising tools.

Turkish law requires these tools to be transparent, accurate, verifiable and fair. The 2026 amendments to the Regulation on Commercial Advertising and Unfair Commercial Practices strengthen consumer protection in digital markets and introduce specific rules on targeted advertising, influencer promotions, discount advertising, AI-generated advertisements, environmental claims and consumer reviews.

For marketplace operators, the key compliance principle is control. Platforms should control how sellers make claims, how discounts are calculated, how sponsored rankings are labeled, how reviews are verified, how Q&A sections are monitored, how personal data is used and how checkout flows are designed. For sellers, the key compliance principle is substantiation. Every claim, price, discount, review and product promise should be truthful and documentable.

The Advertising Board actively enforces misleading advertising and unfair commercial practice rules. In 2026, fines for misleading advertisements and unfair commercial practices may reach 39,916,524 TL, and online violations may also create access blocking and campaign suspension risks.

A compliant online marketplace advertising strategy protects consumers, reduces regulatory exposure and strengthens trust. In Turkey’s digital economy, marketplace success depends not only on visibility and conversion, but also on lawful advertising, transparent pricing, genuine reviews and fair platform design.