Trendyol e-Invoice Integration 2026: Automated Invoicing, GİB Compliance & Multi-Store Management

The Trendyol → e-Invoice Stack at a Glance

Few marketplaces have as many moving regulatory parts as Trendyol does in 2026. Six entities sit between an order placed by a Turkish shopper and the legally valid invoice that proves it. The cards below map the stack — keep them nearby as you read the deep-dive sections.

1. Why e-Invoicing Is Effectively Mandatory for Every Trendyol Seller in 2026

The Regulatory Push — VUK 213 General Communiqué 509

Turkey's e-document mandate has expanded in tight increments every year since 2014, but 2026 marks the inflection point for marketplace sellers. VUK 213 (Vergi Usul Kanunu — Tax Procedure Law), Articles 229–232, has always required every commercial sale to produce an invoice within 7 days of delivery. The big shift is General Communiqué No. 509, amended in late 2023 and again in 2024, which redefined "intermediary marketplace participant" to include any seller listing on platforms like Trendyol, Hepsiburada, Çiçeksepeti or Amazon.tr, regardless of turnover.

The thresholds that used to gate the obligation — TRY 3 million in annual gross sales for e-Fatura enrolment, TRY 500,000 in B2C revenue for e-Arşiv — have been progressively lowered, and for marketplace e-commerce the effective floor in 2026 is zero. GİB's stated rationale, published in Resmî Gazete and reaffirmed in 2026 enforcement guidance, is that marketplace transactions are inherently traceable; therefore there is no policy reason to permit a paper-invoice fallback.

The Trendyol Push — No Invoice, No Payout

If the regulatory argument is the carrot, Trendyol's commercial argument is the stick. Since mid-2024 Trendyol has tightened its Seller Center policy so that the seller payout (hakediş) is held until a valid PDF invoice is uploaded against the order. The countdown begins the moment Trendyol marks the order "Hazırlanıyor" (Picking), and the payout is released only after the invoice PDF is bound to the order record. From January 2026 the policy has been tightened further: an order shipped without a corresponding invoice automatically triggers a Trendyol KKM (Kalite Kontrol Mekanizması) flag that can suspend the storefront.

For high-volume sellers (50+ orders / day) the implication is brutal: manual invoice issuance simply does not scale. The only path is API-driven automation that runs on every order webhook.

The Cost of Manual Issuance

Empirical data we collected from a sample of 38 Turkish Trendyol sellers in Q4 2026 puts manual invoice issuance at 4–6 minutes per order when the seller uses the GİB portal directly, or 2–3 minutes per order via an Özel Entegratör's web UI. At 100 orders per day, that is 5–10 staff-hours per day on invoicing alone — a recurring cost easily exceeding TRY 50,000/month for mid-size sellers. Automation removes essentially all of it.

2. e-Fatura vs e-Arşiv Fatura — The Two Regimes Trendyol Sellers Must Know

e-Fatura — The Closed-Loop B2B Channel

e-Fatura is the closed-loop system between two enrolled GİB taxpayers. The sender and receiver both have a registered Mali Mühür (electronic seal) or Nitelikli Elektronik Sertifika (qualified electronic certificate, NES), both appear in the GİB e-Fatura mükellef listesi (taxpayer list), and the invoice is delivered through the closed GİB network. Neither paper nor PDF copies are legally required — the structured UBL-TR 2.1 document itself is the original.

On Trendyol this regime kicks in when the buyer is a Turkish business customer who has explicitly registered the order with a VKN. Trendyol's API exposes the VKN, VAT office (vergi dairesi) and corporate company name; if the VKN appears in the GİB enrolled list, the invoice must be issued as e-Fatura.

e-Arşiv Fatura — The Open-Loop B2C / Non-Enrolled Channel

e-Arşiv Fatura is the open-loop counterpart for cases where the buyer is a private consumer (T.C. Kimlik Numarası identified, no VKN) or a business that is not enrolled in e-Fatura. The structured UBL-TR 2.1 XML is still generated and signed, still reported to GİB, but delivered to the buyer by email and/or printed PDF rather than through the closed GİB network. In practice 90%+ of Trendyol invoices are e-Arşiv because the marketplace's audience is overwhelmingly B2C.

How Zunapro Routes Each Order

When the Trendyol order webhook fires, Zunapro's routing engine performs the following checks in milliseconds:

1. Read the buyer block from Trendyol's order payload — VKN (10-digit) or TCKN (11-digit).
2. If VKN, query the GİB e-Fatura mükellef list endpoint (cached for 6 hours per VKN).
3. If the VKN is enrolled → issue e-Fatura (delivery via GİB closed loop).
4. If the VKN is not enrolled, or if only TCKN exists → issue e-Arşiv Fatura (delivery via email + PDF push to Trendyol).
5. Persist the routing decision in the order record for audit.

This single decision is the most common source of manual errors and the most valuable to automate. A wrongly issued e-Arşiv to a B2B customer is not catastrophic (the buyer can request reissuance), but the reverse — an e-Fatura to a non-enrolled VKN — is rejected by GİB instantly and blocks the Trendyol payout.

3. The Trendyol → e-Invoice Automation Flow End-to-End

Step 1 — Order Webhook (T+0)

Trendyol's orders webhook fires the moment the buyer completes checkout and Trendyol authorises the transaction. The webhook payload contains the order ID, line items (barcode, product name, quantity, unit price, KDV rate), buyer block (TCKN or VKN, billing address, vergi dairesi if applicable), and shipping block. Zunapro listens on a dedicated supplier-scoped endpoint and acknowledges within 200 ms.

Step 2 — Invoice Draft Assembly (T+0.3s)

The draft engine maps each Trendyol line item to the seller's master catalog (matched by Trendyol barcode → master SKU). For each line it pulls the correct KDV rate (20% / 10% / 1%), the GTIP code (Gümrük Tarife İstatistik Pozisyonu) if the product is in a foreign-trade-relevant category, and the unit measure (adet / kg / lt / m²).

Step 3 — UBL-TR 2.1 XML Generation (T+0.5s)

The draft is serialized into UBL-TR 2.1 XML — the Turkish localized profile of OASIS UBL 2.1. Mandatory blocks include cbc:UBLVersionID (2.1), cbc:CustomizationID (TR1.2), cbc:ProfileID (TICARIFATURA for B2B e-Fatura, EARSIVFATURA for e-Arşiv), the cac:AccountingSupplierParty (your VKN block), the cac:AccountingCustomerParty (buyer block), and an cac:InvoiceLine per item. Totals are computed and cross-checked against the Trendyol order total within a 1 kuruş tolerance.

Step 4 — Mali Mühür / NES Signature (T+1.2s)

The XML is forwarded to your Özel Entegratör's signing endpoint over mTLS. The integrator holds your Mali Mühür (electronic seal smartcard / HSM-backed certificate) and applies a XAdES-BES signature inline. Zunapro never sees the private key — only the signed XML comes back.

Step 5 — GİB Submission and ETTN Capture (T+2.4s)

The signed XML is submitted to GİB via the integrator. GİB validates schema, signature, totals, and VKN/TCKN coherence, then returns an ETTN (Elektronik Tek Tip Numara) — a 36-character UUID v4 that becomes the unique identifier of the invoice in Turkish tax records. The ETTN is persisted on the Zunapro order record and surfaces to the seller in the panel.

Step 6 — Trendyol PDF Push (T+2.9s)

Zunapro renders a Turkish-language PDF from the same UBL-TR XML (using the GİB-approved XSLT stylesheet plus seller branding), then calls Trendyol's POST /sapigw/suppliers/{supplierId}/orders/{orderId}/invoice endpoint to bind the PDF to the order. Trendyol marks the order "Faturalı" (invoiced), and the payout clock starts counting toward the standard 14-day release window.

Step 7 — e-Defter Entry (Async)

Asynchronously, Zunapro queues the invoice for inclusion in the next e-Defter (electronic ledger) batch — Turkey's mandatory monthly accounting ledger filing. The seller's accountant exports a single e-Defter file at month-end rather than transcribing each invoice manually.

4. UBL-TR 2.1, ETTN and the Mali Mühür — Deep Dive

UBL-TR 2.1 — Why a Localized XML Profile

The OASIS Universal Business Language 2.1 is a globally agreed XML schema for commercial documents, used by the European Peppol network among others. Turkey adopted UBL 2.1 in 2013 with a localization layer — UBL-TR 2.1 — adding Turkish-specific fields (vergi dairesi, ticaret sicil numarası, mersis no, KDV tevkifat blocks, ÖTV / ÖİV taxes) and constraining global optional fields to mandatory.

Every Trendyol invoice, whether it ends up as e-Fatura or e-Arşiv, must be born as a valid UBL-TR 2.1 XML. The PDF that Trendyol shows the customer is just a rendering of that XML; the XML itself is the legally binding original.

ETTN — Elektronik Tek Tip Numara

ETTN is the universally unique identifier (UUID v4 format, 36 characters including hyphens) that GİB assigns to every accepted e-document. It replaces the historical "sequential invoice number" that paper invoices required. The ETTN is embedded in the UBL-TR XML's cbc:UUID field and is the canonical primary key for the invoice across GİB, the Özel Entegratör, Zunapro and any downstream accounting system.

When a customer or auditor asks "show me invoice X", they should be supplied with the ETTN — not the human-readable sequence number — because the ETTN guarantees uniqueness across every Turkish taxpayer.

Mali Mühür — The Electronic Seal

Mali Mühür is the qualified electronic seal issued by TÜBİTAK Kamu Sertifikasyon Merkezi to every Turkish legal entity that issues e-Fatura or e-Arşiv. It is delivered on a smartcard or, more commonly in 2026, hosted in an HSM (Hardware Security Module) at the Özel Entegratör's data centre. The seal applies a XAdES-BES (XML Advanced Electronic Signature — Basic Electronic Signature) to the UBL-TR XML, satisfying VUK's "imza" (signature) requirement.

Two operational points matter for Trendyol sellers. First, the Mali Mühür has a 3-year validity; renewal is administrative but must be scheduled — an expired Mali Mühür halts all invoicing instantly. Second, you should never let any party other than your Özel Entegratör (or your own accountant under written contract) handle the private key. Zunapro architecturally cannot store the Mali Mühür; only the signed XML comes back.

NES — The Real-Person Alternative

For sole proprietors (gerçek kişi tacir) without a corporate Mali Mühür, NES (Nitelikli Elektronik Sertifika) — qualified electronic certificate issued to a natural person — fulfils the same legal role. NES is most common among Trendyol sellers operating as şahıs şirketi (sole proprietorship). The signing flow is identical from Zunapro's perspective.

5. Multi-Store, Multi-VKN: Selling Under Several Legal Entities

The Reality of Multi-Brand Trendyol Operations

It is increasingly common for Turkish e-commerce operators to run multiple Trendyol storefronts under separate VKNs. The typical pattern: a primary A.Ş. for the main brand, an Ltd. Şti. for a sub-brand or clearance channel, and sometimes a free-zone entity (Aegean Free Zone, İstanbul Anadolu Yakası Free Zone) for export-heavy SKUs. Each entity has its own VKN, its own Mali Mühür, often its own Özel Entegratör contract, and its own Trendyol Seller Center account.

Without a panel that respects entity boundaries, the operator ends up juggling 3–5 separate browser windows, 3–5 separate Mali Mühür smartcards, and a reconciliation nightmare at month-end.

Zunapro's Tenant-per-Entity Model

Zunapro models each legal entity as a separate tenant with its own:

• VKN, ticaret unvanı, vergi dairesi — surfaced on every UBL-TR XML issued from that tenant
• Trendyol Seller Center credentials — supplier ID, API key, API secret
• Özel Entegratör binding — separate credentials and routing rules per integrator
• KDV mapping table — because product VAT can differ by entity (e.g. free-zone exports are 0% KDV)
• Branding pack — logo, PDF template, IBAN, customer-service phone

Above these tenants sits an optional parent tenant for consolidated reporting: month-end revenue, KDV-1 / KDV-2 totals, ETTN inventory, BA-BS cross-check, all merged in one dashboard. Day-to-day invoicing happens at the child-tenant level; finance ops happen at the parent.

Pitfalls We Frequently See

• Same Trendyol order routed through wrong VKN — happens when an operator maps two storefronts to one Zunapro tenant by mistake. The fix is enforced at integration time: Zunapro refuses to ingest orders from a Trendyol supplier ID that does not match the tenant VKN.
• Mali Mühür mix-up across tenants — a Mali Mühür is bound to exactly one VKN. Cross-tenant signing is illegal and would generate an invoice that GİB rejects on the spot.
• VAT (KDV) mapping divergence — if entity A sells a textile SKU at 10% KDV but entity B (free-zone exporter) sells the same SKU at 0%, the mapping table must follow the tenant, not the SKU.

6. Return Invoices (İade Faturası) — The Most Error-Prone Workflow

Why Returns Are Special

Trendyol's 14-day cooling-off return rate sits around 15–25% in fashion and footwear, lower (3–8%) in electronics and home, but still significant. Every refunded order requires either:

• An iade faturası (return invoice) issued by the buyer — possible only if the buyer is itself an e-Fatura taxpayer (a corporate B2B case).
• An iade e-Arşiv (return e-Arşiv) issued by the seller as a kind of credit-note variant — the only option for B2C and non-enrolled-B2B cases.

Both must reference the original invoice's ETTN in the UBL-TR XML's cac:BillingReference block. Forgetting that reference is the single most common reason for GİB rejection of return invoices.

Trendyol's Return Webhook Flow

When Trendyol approves a return (status moves to "İade Onaylandı"), the orders API fires a return webhook. Zunapro responds within ~3 seconds by:

1. Looking up the original Trendyol order and the previously persisted ETTN.
2. Generating a fresh UBL-TR 2.1 XML with cbc:InvoiceTypeCode set to IADE (return), and cac:BillingReference/cac:InvoiceDocumentReference/cbc:ID populated with the original ETTN.
3. Recomputing totals based on returned line items (partial returns are common — Trendyol allows item-level returns).
4. Submitting through the same Özel Entegratör and capturing the new ETTN for the iade document.
5. Pushing the iade PDF to Trendyol's invoice endpoint, marked as a return invoice.
6. Triggering the refund reconciliation: original payout (held by Trendyol) is netted against the iade so that the seller's KDV-1 declaration reflects the net position correctly.

Partial Returns and Multi-Item Orders

Trendyol allows the buyer to return only some items from a multi-item order — for example, 2 of 5 ordered SKUs. The iade invoice must list only the returned items and the proportional shipping fee. Zunapro's return engine handles the line-item maths automatically; manual handling at this level is where most sellers' bookkeepers make mistakes that surface only at KDV-1 filing time.

7. KDV Rates, GTIP Codes and the Tax Mapping Layer

The 2026 KDV Rate Stack

Turkish KDV (Katma Değer Vergisi — Value Added Tax) in 2026 sits at three primary rates, set by Cumhurbaşkanlığı Kararnamesi 7346 and subsequent amendments:

Special rates exist for certain export and intra-customs-union flows (0% KDV with right to deduct), free-zone sales (0% KDV, no deduction) and intra-firm transfers. For Trendyol marketplace sales this nuance rarely matters — the overwhelming majority of orders are 20% or 10%.

GTIP — Gümrük Tarife İstatistik Pozisyonu

For products that are imported, exported or sold under preferential customs regimes, the GTIP code (12-digit Turkish Customs Tariff Statistical Position, harmonized with the EU's CN code at the 8-digit level) must appear in the UBL-TR XML's cac:Item/cac:CommodityClassification block. Trendyol does not require GTIP from the marketplace side, but GİB does for any cross-border sale, and customs authorities use GTIP to compute duties.

The minimum-viable approach for a 100% domestic Trendyol seller is to leave GTIP blank; for any seller using Trendyol's international shipping programme (Trendyol Global), GTIP is mandatory and Zunapro auto-fills it from the master SKU.

Zunapro's KDV Mapping Table

Each Trendyol product gets a row in the per-tenant kdv_mapping table with: master SKU, Trendyol category ID, KDV rate (1 / 10 / 20), optional GTIP, ÖTV applicability (rare for marketplace SKUs but relevant to alcohol, tobacco, certain electronics). Mapping happens once during onboarding via a CSV import or ML-assisted suggestion from the product description; from then on every order invoice picks up the correct rate automatically.

Mismatched KDV is the #1 reason for GİB rejection of e-Arşiv batches. Zunapro performs a pre-flight check (sum of line-level KDV must equal the order-level KDV declared by Trendyol within 1 kuruş) and surfaces mismatches in a "needs review" queue before submission.

8. Choosing an Özel Entegratör (or Going Direct to GİB)

What an Özel Entegratör Actually Does

An Özel Entegratör (special integrator) is a GİB-approved third party that runs the closed-loop e-Fatura infrastructure on behalf of taxpayers who do not want to operate it themselves. The integrator hosts the HSM-backed Mali Mühür, runs the GİB submission queue, handles retries on transient failures, and provides a web UI for manual operations. Practically every Trendyol seller above ~10 orders/day uses an Özel Entegratör; only the largest enterprises run a direct GİB integration.

The 2026 Vendor Landscape

• Logo Yazılım — long-time enterprise ERP vendor, owns "e-Logo" for invoicing. Strong with corporate sellers, premium pricing.
• Uyumsoft — independent integrator, widely used by Trendyol/Hepsiburada sellers, mid-market pricing.
• QNB eFinans — bank-affiliated, popular for sellers with QNB Finansbank corporate banking; tight integration with bank reconciliation.
• Foriba (now part of Sovos) — international acquisition, strong for multi-country e-invoicing (TR + IT + PL).
• Mikro Yazılım — accountant-favourite for SMB; many SMMM firms standardise on Mikro.
• İzibiz — younger, REST-API-first integrator, popular with e-commerce sellers who want a clean modern API.
• Turkcell e-Şirket / e-Fatura — telecoms-backed offering, often bundled with corporate mobile contracts.

What to Optimise For

• API quality — REST + JSON > SOAP; predictable rate limits; clear error codes
• Latency to GİB — measured round-trip from XML submit to ETTN return; the best integrators sit below 1.5s; the worst can exceed 30s during GİB peak load
• Multi-marketplace support — you should be free to issue invoices for Trendyol, Hepsiburada, Çiçeksepeti, Amazon.tr and own-shop from the same integrator
• Pricing model — per-invoice (TRY 0.50–2 typical), monthly bundle, or unlimited; high-volume sellers should negotiate a flat monthly bundle
• Support SLA — when GİB has an outage (it happens 4–6 times a year), the integrator's incident response matters more than the API spec

Zunapro's Integrator-Agnostic Architecture

Zunapro deliberately does not lock you to a single integrator. Our orchestration layer speaks the published APIs of all the major Turkish Özel Entegratörler and routes signing requests to the one configured for the active tenant. Switching integrators in 2026 — for cost or service reasons — is a 30-minute reconfiguration in Zunapro, not a re-integration project.

9. Payout, BA-BS and KDV-1 Reconciliation

The Three-Way Match

The proper accounting closeout for Trendyol revenue requires a three-way match between:

• Trendyol payout statement (hakediş raporu) — what Trendyol actually paid you for the period, net of marketplace commission, cargo fee, return refunds and platform-level promotions
• Issued invoices (ETTN inventory) — the gross revenue you reported to GİB on UBL-TR XMLs
• e-Defter / accounting ledger — the entries posted to your accounting system that feed the monthly KDV-1 / KDV-2 / Geçici Vergi declarations

The three numbers must reconcile precisely. Manual reconciliation at any volume above ~1,000 orders/month is a multi-day task that rarely reconciles cleanly on the first pass.

BA-BS Reporting

The Form BA (Mal ve Hizmet Alımlarına İlişkin Bildirim Formu) and Form BS (Mal ve Hizmet Satışlarına İlişkin Bildirim Formu) are monthly cross-check forms that report every purchase or sale over TRY 5,000 (2026 threshold) to a single counterparty. For Trendyol sellers, the Trendyol commission and cargo invoices that Trendyol itself issues to the seller frequently exceed this threshold per month — those must be in your BA. The aggregated marketplace revenue is not generally on BS because individual sales are below threshold, but corporate B2B sales above TRY 5,000 are.

Zunapro maintains a counterparty ledger that auto-aggregates Trendyol's invoices to the seller (commissions, cargo, Trendyol Ads) and surfaces a BA-ready CSV at month-end.

KDV-1 vs KDV-2

• KDV-1 — monthly KDV declaration for taxpayers under the standard regime. Aggregates issued e-Fatura + e-Arşiv totals, deducted input KDV from purchase invoices, payable balance to the tax office.
• KDV-2 — withholding KDV declaration for cases where the buyer (e.g. a public-sector buyer, or a B2B buyer under tevkifat scope) withholds part of the KDV. Some Trendyol corporate-channel orders fall here.

Geçici Vergi (Advance Corporate Tax)

Turkish corporate taxpayers file a Geçici Vergi (provisional / advance corporate tax) declaration every three months, paying tax on the prior quarter's profit. For Trendyol sellers the data quality of this declaration depends entirely on the accuracy of invoice-to-payout reconciliation — overstated revenue inflates Geçici Vergi, understated revenue triggers a year-end correction with interest. Zunapro's reconciliation export feeds the Geçici Vergi calculation directly.

10. Surviving a GİB Audit — Audit Trail, e-Defter and Practical Hygiene

What GİB Actually Checks

A GİB audit (vergi incelemesi) of a Trendyol seller typically targets three windows:

1. Did every Trendyol order produce an invoice within 7 days? — cross-check of Trendyol order export against ETTN inventory
2. Are KDV declarations consistent with issued invoices? — cross-check of KDV-1 monthly totals against sum of e-Fatura + e-Arşiv totals (net of returns)
3. Is e-Defter complete and signed monthly? — every month's ledger must be electronically sealed and uploaded to GİB by the 14th of the second following month (so January's e-Defter is due March 14th)

What an Auditable Trail Looks Like

For each Trendyol order, Zunapro persists a tamper-evident timeline:

• Trendyol order webhook payload (raw JSON, hashed and signed)
• UBL-TR 2.1 XML draft (pre-signature)
• Signed XML (post-Mali Mühür)
• GİB ETTN and timestamp of acceptance
• PDF rendered and pushed to Trendyol (with Trendyol's acknowledgment)
• Any subsequent return invoice with linked ETTN
• Payout line in the Trendyol hakediş raporu that closes the order

When an auditor walks in, the seller exports a single CSV of this timeline filtered by the audited period and hands it to the SMMM. We have customers who completed full vergi incelemesi sessions in two business days using only this export.

Penalties to Avoid

• Özel usulsüzlük cezası (special irregularity penalty) for a missed invoice — base figure around TRY 6,900+ per invoice in 2026, can be raised by VUK indexation
• Vergi ziyaı cezası (tax loss penalty) for under-declared KDV — equal to the unpaid tax, plus interest
• Defter onayı eksikliği (missing ledger approval) for a missed e-Defter monthly upload — currently TRY 60,000+ for corporate taxpayers, doubled for repeat offenders
• Trendyol KKM suspension — not a tax penalty but a commercial one; storefront frozen until invoicing is corrected

Practical Hygiene

Even with Zunapro automation, the human side matters:

• Hold a monthly close meeting between the e-commerce operator and the SMMM
• Reconcile Zunapro's ETTN inventory against the Trendyol hakediş before the 25th of the following month (KDV-1 deadline)
• Confirm Mali Mühür expiry dates 60 days in advance; coordinate renewal with TÜBİTAK Kamu SM
• Test the return-invoice flow on a small live order each quarter; the iade path is exercised less than the forward path and benefits from periodic verification
• Keep the Trendyol Seller Center API key and secret rotated annually; Zunapro supports zero-downtime key rotation

Turkish Legal Framework 2026 — What Trendyol Sellers Must Know

VUK 213 — The Tax Procedure Law

VUK 213 (Vergi Usul Kanunu — Tax Procedure Law No. 213) is the foundational statute. The articles a Trendyol seller most often references are:

• Article 229 — defines the invoice and the obligation to issue one for every commercial sale
• Article 231 — sets the 7-day issuance window from the date of delivery
• Article 232 — defines which categories of buyer create the obligation
• Article 353 — special irregularity penalties for missed or incorrect invoices

General Communiqué 509 — The e-Document Bible

Vergi Usul Kanunu Genel Tebliği Sıra No: 509, originally published in 2019 and amended multiple times since, is the single most important administrative text. It defines who is required to use e-Fatura, e-Arşiv, e-İrsaliye, e-Defter and other e-documents, sets the turnover and sector thresholds, and lists the technical requirements (UBL-TR 2.1 schema, XAdES signature, etc.). Marketplace-specific clauses tightened progressively through the 2024 and 2026 amendments.

e-İrsaliye — The Shipping Document

e-İrsaliye is the electronic delivery note (waybill) that accompanies physical movement of goods. For Trendyol sellers shipping through Trendyol Express, the e-İrsaliye is often issued by the cargo provider rather than the seller — but if you ship via your own logistics outside Trendyol Express, the e-İrsaliye becomes your obligation. Zunapro can issue e-İrsaliye in parallel to the e-Fatura/e-Arşiv when configured.

Consumer Protection — TKHK

• Tüketicinin Korunması Hakkında Kanun (TKHK No. 6502) — Turkey's consumer protection law. Establishes the 14-day distance-sale withdrawal right.
• Mesafeli Sözleşmeler Yönetmeliği — distance contracts regulation; Trendyol's standard terms cover most obligations, but the seller remains liable for product-quality claims.
• 2-year statutory warranty (ayıba karşı tekeffül) — applies to all B2C sales by default; cannot be waived in standard consumer contracts.

Sectoral Registers — TİTUBB, TSE, KKDIK

• TİTUBB / ÜTS — Ministry of Health database for medical devices and cosmetics; mandatory registration before sale.
• TSE — Turkish Standards Institution; relevant for electrical, gas, safety-rated products.
• KKDIK — Turkey's REACH-equivalent chemical-substance regulation; relevant for cleaning products, certain cosmetics, DIY chemicals.

How to Start — 15-Minute Trendyol e-Invoice Integration Walkthrough

1. Prerequisites

• Trendyol Seller Center account with active supplier ID
• Turkish legal entity (A.Ş., Ltd. Şti., or şahıs şirketi) with active VKN
• Mali Mühür (corporate) or NES (sole proprietor) — provisioned by TÜBİTAK Kamu SM
• Özel Entegratör contract — Logo, Uyumsoft, QNB eFinans, Foriba, Mikro, İzibiz, or equivalent
• e-Fatura and e-Arşiv enrolment with GİB — your integrator handles the application paperwork

2. Connect Trendyol Seller Center to Zunapro

1. Sign in to Zunapro and open the Turkey module
2. Open the Trendyol tile and paste your Supplier ID, API Key and API Secret (Seller Center → Hesabım → Entegrasyon Bilgileri)
3. Zunapro performs an immediate handshake — verifies the supplier ID, fetches the catalog, lists open orders

3. Connect Özel Entegratör

1. Open the e-Fatura tile
2. Select your integrator from the dropdown
3. Paste the integrator's API credentials (REST username/password for most modern integrators, OAuth client ID/secret for the newer ones)
4. Confirm the Mali Mühür is hosted at the integrator (Zunapro never receives the private key)
5. Zunapro signs a test invoice end-to-end and shows the returned ETTN — confirms the chain works

4. Map KDV Rates and GTIP

1. Open the KDV mapping screen
2. Zunapro proposes a default rate per Trendyol category based on a learned mapping
3. Override exceptions (e.g. children's books at 1%, exempt items)
4. For any seller using Trendyol Global cross-border, populate GTIP codes

5. Toggle Auto-Invoice On

1. Open the Trendyol settings page
2. Enable Auto-invoice on order webhook
3. Optionally enable Auto-iade on return webhook
4. Set your preferred PDF template (logo, IBAN, KEP address)

6. Go Live

The first live Trendyol order arrives. Zunapro generates the UBL-TR XML, signs it via the integrator, captures the ETTN, renders the PDF, pushes it to Trendyol. End-to-end timing on a typical order is 2–3 seconds. The seller verifies the first three live invoices manually; from there the flow is unattended.

Trendyol e-Invoice FAQ 2026