Glossary / Single Window System (Tek Pencere Sistemi)
Single Window System (Tek Pencere Sistemi) — explained
The Single Window System is the application and document system, run by the Ministry of Trade, through which the permits, approvals and conformity documents required from different public authorities during customs procedures are obtained electronically from a single point.
The system was established by Prime Ministry Circular No. 2012/6, published in the Official Gazette of 20 March 2012, which also assigned the task of running it to the Ministry of Trade. Every document produced within the system is given a 23-digit document ID number; on the customs declaration, it is this number that is declared, not the paper document itself.
The problem the system solves is fragmentation. If the control certificate required for a shipment came from one ministry, the conformity letter from another authority and the permit from a third body, each of these used to mean a separate application and a separate flow of paperwork. The Single Window System channels these applications through a shared route and produces the result as an electronic document; because the document is only ever created electronically, the risk of forged paperwork is also largely closed off.
There are two different flows within the system. Where the relevant authority’s own system is integrated with the Ministry’s infrastructure, the document arrives electronically directly from that authority; where there is no integration, the application is made through the Ministry, which publishes general user guides for this second flow. For the party responsible, the outcome is the same either way: they end up with a document ID number and enter that number on the relevant line of the declaration.
The number is also used to track balances. For permits granted on the basis of quantity or value, the system tracks how much of the document has been used; subsequent shipments relying on the same permit are deducted from the remaining balance. This means a single permit document can serve not just one declaration, but a series of transactions until its balance is used up.
When You Encounter It
The system comes into play right after the GTİP is determined: as soon as the permit or conformity document required for the product is identified, the application is made through the Single Window System. There are two ways in — the Single Window System link under the Ministry of Trade menu on the e-Devlet portal, or the Ministry’s own application address. Either way, identity verification is carried out through e-Devlet.
The point where things usually get stuck is authorisation. A user who will apply independently needs to have the "Single Window" authorisation defined on their account, and this authorisation does not come automatically with e-Devlet; it has to be requested from the relevant customs directorate. When a company is importing for the first time, this step is often overlooked, and when the application screen fails to open, the problem is assumed to be with the system — when in fact what is missing is the authorisation.
A company does not have to carry this burden itself. At a company that uses customs brokerage services, applications are handled by the broker under the customs power of attorney that has been drawn up; working out from the outset which document is required from which authority for which product is part of the same job. This identification and follow-up is carried out as part of our Customs Brokerage service.
What It Doesn't Cover
- The Single Window System does not grant permits; the relevant authority grants the permit. The system is only the channel through which the application and the document travel — whether the application is rejected, found incomplete or requires an additional document is entirely a matter for that authority’s own legislation.
- Having obtained access authorisation for the system does not mean an application will be accepted. Authorisation opens a door; the outcome is determined by the product’s compliance with the legislation.
- How long an application takes to be concluded does not depend on the Single Window System. The timing is determined by the issuing authority’s own workings, so we cannot commit to a date; plan for it at the latest when the shipment is decided.
Often Confused With
| Comparison | Difference |
|---|---|
| Single Window System (Tek Pencere Sistemi) vs BİLGE System | BİLGE is the system in which the customs declaration is registered and processed. The Single Window System, by contrast, is where the permit and conformity documents to be entered on the declaration are obtained. The order is clear: the document is born in the Single Window, and its number is entered on the declaration in BİLGE. |
| Single Window System (Tek Pencere Sistemi) vs e-Devlet Portal | e-Devlet is the identity-verification gateway through which you log into the Single Window System; it is not the system itself. Anyone with an e-Devlet account can see the link, but making an application also requires the "Single Window" authorisation obtained separately from the customs directorate. |
Frequently Asked Questions
How do you log in to the Single Window System?+
You log in through the Single Window System link under the Ministry of Trade menu on the e-Devlet portal, or through the Ministry’s application address. Identity verification takes place via e-Devlet; for the application screens to open, the account also needs to have the Single Window authorisation defined.
How do you get Single Window System login authorisation?+
Users who will make independent applications need to obtain Single Window authorisation from the relevant customs directorate. The authorisation does not come automatically with an e-Devlet account; the application to the customs administration is made with documents showing the company’s representation authority.
Which authority runs the Single Window System?+
The system is run by the Ministry of Trade. Its establishment is based on Prime Ministry Circular No. 2012/6, published in the Official Gazette of 20 March 2012; the authorities that issue the documents are the other public bodies that take part in the system under their own legislation.
What is the document ID number in the Single Window System?+
It is the 23-digit number generated for every document issued in the system. On the customs declaration, this number is declared in place of the paper copy of the document; for permits granted on the basis of quantity or value, the remaining balance of the document is also tracked through this number.
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Related Terms
Where This Term Comes Up in Our Work
Single Window System (Tek Pencere Sistemi) is one of the documents we track in our customs brokerage service.
Customs BrokeragePreparation, registration, and tracking of your import and export customs declarations.The Turkish original of this page was reviewed by our licensed customs broker. This translation is provided for information; the Turkish version prevails.
Source
Republic of Türkiye Ministry of Trade — Customs Guide: Single Window System — Establishment of the system: Prime Ministry Circular No. 2012/6, published in the Official Gazette of 20.03.2012.
Last updated: August 22, 2026