Turkey's 10-Day Lowest Price Rule: Can Your E-Commerce Software Prove Every Discount? A November 2026 Technical Guide

Short answer: Turkey's 10-day lowest price rule has applied to discount advertising for goods since 1 August 2026. The pre-discount price, which most websites show struck through, must be the lowest price applied in the 10 days before the discount starts. If a product is sold in more than one channel, only the prices in the channel where the discount runs count. For perishable goods and for services, the previous price is the reference. The burden of proof is on the seller, so your systems must be able to prove six things: the lowest price of the past 10 days in each channel; campaign dates and scope; the calculation for loyalty and conditional campaigns; order-linked review verification and rejection notices; disclosures for targeted ads and personalised prices; and AI labels.

We wrote this guide for e-commerce and marketing managers who sell on their own website and on marketplaces, and for the software teams that run a campaign engine, an ERP–marketplace integration or a custom platform. It is also relevant for founders and international brands that sell into the Turkish market, directly or through Turkish partners. We based the rules on the official texts in the Official Gazette (Resmî Gazete, where Turkish laws and regulations are published) and on mevzuat.gov.tr, the official legislation database. We also used the guideline on price and discount advertising (the "Guideline") issued by the Advertising Board (Reklam Kurulu), the Ministry of Trade's board that decides on advertising violations, and the Ministry's announcements. Where something is our own engineering recommendation, we say so. This is a technical guide, not legal advice. This article is up to date as of 31 October 2026.

When did Turkey's 10-day lowest price rule and the related obligations take effect?

Some summaries still say 30 days, or treat the review rules as new in 2026. But the amendment to the Regulation on Commercial Advertising and Unfair Commercial Practices (the "Regulation") published in Official Gazette No. 33297 of 1 July 2026 did not create everything from scratch. If you do not comply with a rule that has applied since 2022, the work ahead is not a new project. It is an old gap you need to close. Unless another source is named, the article numbers below refer to the Regulation.

The Advertising Board's guidelines apply together with the Regulation (Additional Article 1), but they cannot be read in a way that contradicts it (Guideline Art. 9(3)). So use the logic of the January 2024 Guideline, which is still published, but not its 30-day examples. The burden of proof is on the seller (Law No. 6502 on Consumer Protection, Art. 54(3) and 61(6); Regulation Art. 9(1)). Under Guideline Art. 8(1), you are also responsible, as the advertiser, for discount announcements on your own website.

Enforcement and fines: what are the amounts in 2026?

On 28 October 2026, the Ministry of Trade announced that it will monitor November discount ads in all media. For internet advertising, the 2026 fine band is 1,083,706–10,837,065 TL (Turkish lira) per violation (Law No. 6502, Art. 77(12)(e)). The range of 99,339–39,916,524 TL in the announcement covers all media. For unfair commercial practices, such as rejecting reviews, the band is 108,370–1,083,706 TL, or 1,083,706–10,837,065 TL if the breach is nationwide (Art. 77(13) of the same law). The amounts are updated every 1 January.

On 8 October 2026, the Advertising Board decided on 161 files. It issued stop orders in 136 of them and imposed administrative fines totalling 17,176,744 TL. The findings included struck-through prices that were not based on the lowest price of the last 10 days, and breaches in easily accessible loyalty card programmes. Some of last year's complaints about "Efsane Kasım" ("Legendary November") sales campaigns were decided in December 2025 (93 violations in 108 files, 12,905,818 TL in fines). So your evidence must still be ready weeks after the campaign ends.

How is the pre-discount price calculated?

"When determining the pre-discount price, the lowest price applied in the ten days before the start date of the discount is taken as the basis in advertisements for the sale of goods; in advertisements for perishable goods such as fruit and vegetables, and for services, the price immediately before the discounted price is taken as the basis." (Regulation Art. 14(3), our translation)

In software, we recommend building this as a reference price service. The campaign engine, the banner template and the product page do not calculate the struck-through price themselves; they all ask this service.

Per-channel calculation

Under Art. 14(5), the reference price is based only on the price in the channel where the discount runs. If a product costs 1,000 TL on your website and 900 TL on a marketplace, the struck-through price in a marketplace discount cannot be 1,000 TL. So the service must take the SKU, the variant and the channel together as input. It is also a cautious choice to include prices that applied for only a few hours in a day: a price snapshot taken once a day will miss a flash sale that opens in the evening and closes at night.

Chained campaigns: from 11.11 to Efsane Cuma (Black Friday)

Earlier discounted prices also count as "applied prices". Let us adapt the Guideline's example to 10 days. You cut a 1,000 TL product to 800 TL on 11 November, the day of the 11.11 sales, and keep that price until 20 November. Efsane Cuma ("Legendary Friday") is the name many Turkish retailers use for Black Friday. For an Efsane Cuma campaign that starts on 27 November, the reference period is 17–26 November, and the lowest price in that period is 800 TL. A new price of 700 TL is therefore a 12.5% discount, not 30%. If the 11.11 discount ends before 17 November and the price goes back to 1,000 TL, the Efsane Cuma reference is 1,000 TL again. The marketing team should make this decision knowingly.

Under Guideline Art. 7(3), the reference price may be shown throughout the discount period you announced. That is why we recommend calculating the reference at the start of the campaign and fixing it in the campaign record. This is not wording from the Regulation; it is an implementation choice based on Regulation Art. 14(3) and Guideline Art. 7(3). Guideline Art. 7(3) also requires the reference to be set again for every price reduction. So deepening a discount or announcing a new campaign needs a new calculation that includes the earlier discounted prices.

New products, perishable goods, recommended prices

• Perishable goods and services: The previous price is the reference. The Guideline defines these goods as "agricultural and food products that can spoil within 30 days of their production date" (Art. 4(b)). Keep this as a flag on the product record.
• Newly listed products: Guideline Art. 7(12) uses the lowest price applied since the day the product went on sale. Applying this to products with less than 10 days of history is our recommendation.
• Recommended prices and duplicate listings: The recommended retail price cannot be shown as if it were the reference (Guideline Art. 7(8)). Discounting the same product at different rates in different listings on the same platform also counts as a breach (Art. 7(9)).

How should you keep e-commerce price history?

The Advertising Board's Guideline (Art. 7(6)) requires proof from "receipts, invoices or similar documents, or log records" for sales in the same channel. An "old price" column in the product table, or an Excel export taken overnight, does not show changes during the day or who made them. We recommend an append-only price ledger: it adds every change as a new row and never updates or deletes rows. Each row should hold at least:

• sku, variant_id and channel (website, app, each marketplace and each store as a separate value)
• The effective price including VAT, the currency, the price type (list, campaign, member), the campaign ID and the validity range (valid_from, valid_to)
• The source (admin panel, ERP, marketplace API, bulk upload) and the person or integration that made the change
• The time of recording and a hash of the previous row, so that any later tampering can be detected

Because rows are never updated afterwards, valid_to is filled only for prices whose end is known up front (a campaign price, for example); if it is empty, the price applies until the next row starts. In this ledger, the reference price is a simple range query:

SELECT MIN(gross_price) FROM (
  SELECT gross_price, valid_from,
         COALESCE(valid_to,
                  LEAD(valid_from) OVER (ORDER BY valid_from),
                  :start) AS valid_until
  FROM price_ledger
  WHERE sku = :sku AND variant_id = :variant AND channel = :channel
) p
WHERE valid_from < :start
  AND valid_until > DATE(:start) - INTERVAL 10 DAY;

If the query returns nothing (NULL), or if the ledger does not cover the whole reference period (for a new product, the whole time since it went on sale), the service must not produce a struck-through price either. Feed the ledger from every place where prices change: ERP updates, marketplace integrations and Excel uploads can bypass the admin panel's records. On marketplaces, record the live price read back from the API as well as the price you sent. We covered price and stock sync between the ERP and the website in our article on ERP and e-invoicing integration. In custom set-ups, we build this layer as part of our API integration service.

An evidence pack for every campaign

For every campaign, prepare a pack that you can export with one click: the campaign record, the reference price per SKU and the ledger rows used in the calculation, same-channel orders and invoices from the reference period, and the creatives that were published. Under Guideline Art. 9(2), correcting a breach afterwards does not remove liability, so the evidence must be created during the campaign. Put the pack and the ledger in a backup set-up that is independent of the primary database, and agree the retention period with your legal team.

Which checks should your campaign engine have?

Most of the breaches listed in the Ministry's announcement of 28 October can be prevented when a campaign is set up: campaigns without dates, stacked rates such as "70% + 10% + 5%", loyalty and conditional campaigns that break the rules, and hidden exceptions. The checks we recommend:

• Dates and quantities: No campaign can go live without a start date and an end date. Show any limited quantity, how long the price applies and any stock limit (Art. 14(1), 13(9)).
• One final rate: If discounts are stacked, the engine calculates and shows the final rate and the final price against the reference price. Giving the impression of a bigger discount than the real one breaches Art. 14(2).
• Checking "up to" claims: Guideline Art. 5(5) requires "up to …" wording in a readable size and a scope that meets reasonable expectations. The engine compares the rate on the banner with the real product rates and shows the campaign manager how many products reach that rate. Use words such as "flat", "all" and "everything" ("net", "tümü", "her şey") only if the offer applies to all products in the store or in the relevant category (Guideline Art. 5(3)).
• Loyalty and conditional campaigns: Apply the same date and reference price logic to easily accessible loyalty programmes (Art. 14(6)) and to conditional sales such as "buy 3, pay for 2" (Art. 14(7)).
• Real urgency: The countdown runs from the real end time, and a "last 3 items" badge comes from real stock (Annex A(7), Guideline Art. 5(7)).
• Checkout: Paid options are not pre-ticked (Guideline Art. 5(2)), and the delivery fee is shown together with the price (Guideline Art. 5(1), Regulation Art. 13(5)). Also test the flow against the ban on steering interfaces in Annex A(22).

How does the "only buyers may review" rule affect your review system?

This rule did not arrive in 2026: the core review rules have been in force since 1 March 2022. The 2026 amendment added the following. Reviews taken from channels where the purchase cannot be verified may not be published. Publication rules may not block reviews or limit them to certain topics. Reviews under separate headings, such as product, delivery and seller, must all be shown in the same area. Reviews used in other media must reflect the overall picture, and unverified reviews may not be used in advertising (Art. 28/B). The Regulation also added a definition of "consumer reviews" that covers ratings and stars as well (Art. 4(t)).

On 13 August 2026, the Advertising Board fined a company 2,167,412 TL. The company had refused to publish a buyer's review on a general ground, without a concrete explanation, and had left it to the consumer to resubmit the review under another category. The workflow we draw from this decision:

1. After delivery, send a single-use invitation link tied to the order line.
2. Use a closed list of rejection reasons in moderation. With every rejection, send the consumer an explanation specific to that review immediately.
3. Do not reject a review that was written under the wrong heading. Move it to the right heading yourself, without changing its content.
4. Keep published reviews online for at least one year. Base the default sort order on an objective criterion such as date or rating, not on a filter that removes negative reviews.
5. Once a resolution has been verified, publish the resolution note next to the original review. Pass only verified reviews to advertising.

"Why am I seeing this ad?" Targeted advertising and AI labels

Under Art. 25/A, targeted advertising based on analysing online behaviour, past preferences, location or demographic data is allowed only if the consumer is told, directly and in an easily accessible way, which criteria were used and how to change them. Profiling-based targeted ads are banned for people who are known, or should reasonably be known, to be children. What this means in software:

• In personalised ad slots, a "Why am I seeing this ad?" component that lists the criteria in plain language and links to the preference centre.
• A rule that switches off profiling when age signals point to a minor.
• A personalised price shown in the same area as the current sale price, together with a notice that it is personalised (Art. 13(10)). Dynamic pricing that uses no personal data is not covered by this (Guideline Art. 6(11)).

Art. 25/A does not replace the privacy notice and, where needed, the explicit consent processes under KVKK, the Turkish personal data protection law. The cleanest approach is to design both in the same preference centre. We handle this part together with our KVKK and GDPR compliance work.

Art. 18(8) requires a clear statement when an ad uses AI or other software in a way that significantly affects consumers' economic behaviour, or features AI characters that cannot be told apart from humans. Art. 27(12) bans showing an AI-generated digital copy of a real person as if that person used or recommended the product. The practical solution is to add a "made/edited with AI" flag to every image and video in your DAM/CMS, and to let ad templates print the label automatically from this flag when it is needed. In ads with social media influencers, the label "Reklam" (advertisement) or "Tanıtım" (promotion) must appear together with the advertiser's name or account, without the viewer having to scroll (Art. 23/A). For the EU side, see our article on Article 50 of the EU AI Act.

November 2026 calendar: how does Turkey's 10-day lowest price rule affect 11.11 and Black Friday?

According to ETBİS, the Ministry of Trade's e-commerce information system, e-commerce volume in November 2025 was 41.5% higher than in November 2024. If a campaign starts on the following days, the reference periods are:

If your campaigns run all month, the reference period is recalculated from the start date of each discount announcement.

What should you do this week if you have no price history?

A complete price history cannot be created retrospectively. If you cannot start recording before 1 November, the realistic target is not 11.11 but the Efsane Cuma window and your 2027 campaigns. The order we recommend:

1. Start recording today. Record the current price of every SKU, variant and channel, then add every change.
2. Without evidence, do not use struck-through prices or percentages. Under Guideline Art. 7(3), you can set a new sale price without advertising a discount. Phrases such as "huge deals" ("dev fırsatlar") also create the impression of a discount and require a reference price on the product page (Guideline Art. 7(5)).
3. Do not raise prices just before a campaign. It creates a picture that is hard to defend against the ban in Art. 14(2) on giving the impression of "a bigger discount than there really is".
4. Start a document and creative archive: same-channel orders and invoices, marketplace price history, ERP change logs, campaign dates, scope, rates and every creative you publish.
5. Compare before you publish. Compare the calculated reference price with the struck-through price in the creative, and require approval for any difference.

Questions that are still unclear

The legislation is not clear on the following points; discuss them with your legal adviser:

• Are on-site product recommendations and sponsored listings targeted advertising within the meaning of Art. 25/A?
• Do Google or Instagram reviews embedded on your site count as a channel where the purchase cannot be verified?
• Are the mobile app and the website separate sales channels?
• Are coupons and "sepette indirim" (a discount applied in the basket) covered by Art. 14(7)? The Regulation brought conditional sales into scope, but it does not mention coupons.
• When does a loyalty programme count as "easily accessible"?

How Partnerfy can help

We treat this as a data and process problem, not as a legal text. First, we map every point where prices change (admin panel, ERP, marketplace integrations, bulk uploads) and connect them all to a single immutable price ledger. Then we add the reference price service to your campaign engine as a pre-publication check, build a rejection flow with stated reasons into your review module, and add an export that produces the evidence pack for each campaign with one click. We hand over the points that need legal interpretation to your legal adviser as open questions. A campaign engine, marketplace, shipping and e-invoice integrations, and a moderated review module are also parts of Kambloo, our sales-focused e-commerce platform that goes live at New Year 2027. So we know from our own product how these modules connect. For details, see our e-commerce solutions or contact us.

Sources

• Official Gazette, 1 July 2026, Issue 33297: amendment to the Regulation on Commercial Advertising and Unfair Commercial Practices (in Turkish)
• Regulation on Commercial Advertising and Unfair Commercial Practices, consolidated text (in Turkish)
• Law No. 6502 on Consumer Protection (in Turkish)
• Communiqué on the administrative fines to be applied in 2026 under Article 77 of Law No. 6502 (in Turkish)
• Official Gazette, 1 February 2022, Issue 31737: amendment to the Regulation on Commercial Advertising and Unfair Commercial Practices (in Turkish)
• Official Gazette, 11 October 2025, Issue 33044: amendment to the Price Tag Regulation (in Turkish)
• Advertising Board: Guideline on Advertisements Containing Price Information, Discount Sale Advertisements and Commercial Practices (9 January 2024, decision 341; in Turkish)
• Ministry of Trade: Communiqués and guidelines (in Turkish)
• Ministry of Trade announcements (in Turkish): 28 October 2026, 16 October 2026, 19 August 2026, 21 December 2025
• ETBİS: Outlook of E-Commerce in Türkiye 2025 (in Turkish)

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