How Is Customs Duty Calculated? A Step-by-Step Worked Guide

The base for duty: customs value

Most duty items derive from a single figure: customs value. This figure is not the price of the goods on the invoice. Freight and insurance costs incurred up to the point the goods enter the Turkish customs territory are added to the sale price; Article 27 of Customs Law No. 4458 lists these additions. The result is a base equivalent to CIF even if your delivery term is EXW or FOB. Check the exceptions separately: the declaration stamp duty is a flat amount, anti-dumping duty can also be charged as a fixed amount per unit, and the base for the Resource Utilisation Support Fund (KKDF) is the import price, not the customs value.

Other items that must be added to the sale price:

• Commissions paid by the buyer (except buying commission)
• Packaging and container costs
• Inputs and tooling supplied free of charge or at reduced cost by the buyer, and engineering, development, design and drawing work carried out outside Türkiye
• Royalty and licence payments tied to the goods and required as a condition of sale
• Loading, handling and port costs incurred abroad that are not included in the invoice price

For the last item, check the delivery term: under FOB, the cost of the port of departure and export clearance is already in the seller’s price and is not added a second time.

Inland carriage after the point of entry, assembly costs and after-sales service charges do not enter the customs value as long as they are shown separately in the declaration. If the transaction-value method cannot be used (where a relationship has affected the price, or for goods supplied free of charge), the other methods listed in the law kick in in sequence; the order of the last two methods (deductive value and computed value) can be swapped at the declarant’s request.

Duty is calculated in Turkish lira. The exchange rate used is the CBRT selling rate in effect on the date the customs obligation begins — the date the declaration is registered — not the buying rate and not the rate on the invoice date.

The two things that set the rate: HS code and origin

The duty rate is tied not to the commercial name of the goods but to the HS code (Harmonised System / Customs Tariff Statistical Position); two items in the same product family can end up on different rates if they fall under different codes.

The second determining factor is origin — where the goods were manufactured, not where they were shipped from. Under the same HS code, the rate can be zero depending on origin, additional customs duty can apply, or anti-dumping duty can come into play.

Do not memorise rates, and do not copy them from another importer’s declaration. Current rates are published in the Official Gazette as part of the Import Regime Decision and its annexes, and can be looked up by HS code through the Ministry of Trade’s tariff enquiry screens. If you are unsure of the classification, apply for a Binding Tariff Information (BTI) ruling; the application is submitted electronically to the Ministry of Trade through the regional customs and foreign trade directorates, and the ruling given is binding on the administration.

The order in which duty items stack up

The most common mistake starts here: the items do not sit side by side — they stack on top of each other.

Order	Item	Base
1	Customs duty	Customs value
2	Additional customs duty	Customs value
3	Anti-dumping duty	Customs value, or a fixed amount per unit
4	Excise duty (ÖTV) (only for goods on the excise lists)	If ad valorem, the elements making up the VAT base; a fixed amount on some lists
5	VAT	Value + duties paid on import + expenses incurred up to registration that have not already been taxed

The VAT base is not the price of the goods. Under Article 21 of the VAT Law, the base includes the value used for customs duty purposes, every tax, duty, charge and levy paid on import, and any other expenses and payments made up to the date of registration that have not already been taxed. This condition makes a difference: domestic services invoiced with VAT already charged on them (consultancy, delivery-order fees) do not enter the import VAT base. Storage, warehousing and terminal services provided in the customs area, however, are exempt from VAT and are therefore added to the base.

The base for ad valorem excise duty is also the elements making up the VAT base: value, duties paid on import (including anti-dumping) and untaxed expenses. For goods on List (I), such as fuel, and for some other items, excise duty is a fixed amount instead — charged per unit, with no link to value.

KKDF arises on imports made under non-cash payment methods (deferred payment, cash against goods, acceptance credit); its base is not the customs value but the import price transferred. On some agricultural products a housing fund charge may be levied per kilogram, and some electronic goods incur a banderole fee; the scope should be confirmed by HS code.

A step-by-step worked example

The rates below are illustrative only and do not belong to any real HS code. Scenario: importing machinery from a country with no free trade agreement, outside the scope of excise duty, paid in cash — so there is no KKDF.

First, the value is built up:

Item	Amount
Price of goods (FOB)	20,000
Freight	1,500
Insurance	200
Customs value	21,700

Because port-of-departure costs are included in the seller’s price under FOB, there is no separate handling item.

Then the duties stack up:

Step	Calculation	Amount
Customs duty (assumed 5%)	21,700 × 0.05	1,085
Additional customs duty (assumed 10%)	21,700 × 0.10	2,170
Storage cost in the customs area, exempt from VAT	—	300
VAT base	21,700 + 1,085 + 2,170 + 300	25,255
VAT (assumed 20%)	25,255 × 0.20	5,051
Total duty	1,085 + 2,170 + 5,051	8,306

The flat declaration stamp duty is small enough that it has been left out of the example.

If VAT were mistakenly calculated on the price of the goods alone, it would come to 20,000 × 0.20 = 4,000. The 1,051 difference is the unbudgeted cash need that shows up at customs.

How a preferential certificate of origin changes the calculation

If the same goods originate in a country with a free trade agreement and arrive with a valid EUR.1, customs duty drops to zero. In the example, it is also assumed that additional customs duty does not apply:

Item	Without a certificate	With a preferential certificate of origin
Customs duty	1,085	0
Additional customs duty	2,170	0
VAT base	25,255	22,000
VAT	5,051	4,400
Total duty	8,306	4,400

Whether additional customs duty applies under preferential origin is determined by checking the country-group column in the annex to the relevant decision. In some agreement partners it does not apply at all; in others it continues to apply at a different rate — the certificate alone does not zero out additional customs duty.

The saving does not come only from customs duty; because the base shrinks, VAT falls too. For the certificate to work, the goods must satisfy the origin rules in the agreement; these rules are written product by product. Nor is it enough for the certificate simply to have been issued: the customs authority of the country of destination can send it for subsequent verification, the verification is carried out by the competent authority of the exporting country, and if origin is not confirmed, duty is claimed back retroactively.

A point often confused in trade with the EU: A.TR certifies free-circulation status, not proof of origin. Goods of third-country origin can enter free circulation in the EU and travel with an A.TR; anti-dumping duty and additional customs duty still apply based on the actual origin.

What pushes the value up: surveillance

The most common form of surveillance (gözetim) is value-based: for certain HS codes, if the declared unit value falls below the threshold set in the relevant communiqué, a surveillance document is required. The document is obtained from the Ministry of Trade’s General Directorate of Imports, and the process takes time. Quantity-based surveillance, along with safeguard measures and quotas, are separate arrangements.

A second route often resorted to is declaring the value pulled up to the threshold; this carries a legal risk. Declaring value other than the true sale price is contrary to the rule that value be declared at the real sale price, is challenged under post-clearance control, and makes deduction of the excess VAT paid disputable. If this route is chosen, filing the declaration with a reservation and preserving the right to litigate should be considered. When value rises, every item stacked on top of it, and VAT, rises too. The threshold and scope change through communiqués; check by HS code before ordering.

When duty is due, and whether there is an exemption

Duty is assessed on registration of the declaration. Goods are not released before duties are paid or secured by a guarantee; the period allowed for payment after notification is set by legislation and is short. Where there is a dispute over value or a laboratory test is pending, the goods can be released against a guarantee; that amount stays blocked until the guarantee is released. A comprehensive guarantee and AEO (YYS) status ease this burden.

Exemptions and reliefs change the calculation from the outset: machinery under an investment incentive certificate, inputs arriving under the inward processing regime, samples. For low-value goods arriving by post or express courier, a single flat duty applies instead of a normal declaration, with the rate varying by origin. Thresholds and rates are set by presidential decree and have changed several times in recent years; confirm before ordering.

Common mistakes and a pre-order checklist

• Calculating VAT on the price of the goods alone. The base is the total including customs duty and other duties.
• Not adding freight and insurance to the value. An EXW/FOB purchase does not exclude these from the declaration.
• Adding the same cost twice. On an FOB/CIF purchase, do not write the port-of-departure cost again when it is already in the seller’s price.
• Using the exchange rate on the invoice date. The rate that applies is the CBRT selling rate in effect on the date of registration.
• Confusing origin with the country of shipment. Loading from an EU port does not show that the origin is the EU.
• Leaving royalties, tooling costs or free-of-charge inputs out of the declaration. These are claimed back later, with a penalty and default interest, under post-clearance control.
• Failing to document the method of payment. If cash payment cannot be evidenced with a bank receipt, KKDF is assessed afterwards.
• Leaving the surveillance and anti-dumping check until after ordering. Both can fundamentally change the unit cost.
• Treating total cost as duty alone. Storage, demurrage, delivery-order and consultancy fees are not duties but still require cash the same day. Amounts invoiced with VAT do not enter the import VAT base; exempt storage and terminal charges incurred in the customs area do.

Before placing an order, follow this sequence:

1. Confirm the HS code; if in doubt, submit the BTI application before ordering.
2. Determine the origin; find out in writing from the supplier whether a preferential certificate can be obtained.
3. Check whether surveillance, anti-dumping duty or a quota applies to that HS code, by country column.
4. Read the customs duty, additional customs duty, any excise duty and VAT rates from the legislation.
5. Establish whether the method of payment gives rise to KKDF.
6. Build up the value and calculate the total duty and the cash needed at customs.