Turkish Customs issues both an additional customs assessment and an administrative penalty. Learn how foreign companies can challenge the underlying duty, penalty, calculation, classification, customs value, origin and procedural defects.

A foreign company may receive two substantial liabilities after a Turkish customs inspection, secondary control or post-clearance audit:

an additional customs duty assessment

and

an administrative monetary penalty.

This frequently occurs where Customs alleges that the original declaration resulted in an underpayment because of an incorrect tariff classification, customs value, origin, quantity or other declaration element.

The important point is that the additional customs liability and the administrative penalty should not automatically be treated as one indivisible issue.

Both may potentially be challenged, and different legal arguments may apply to each.

This distinction is especially important in 2026. The Ministry of Trade reported that secondary controls and post-clearance audits resulted in TRY 10.1 billion in additional assessments and penalty decisions during the first eight months of 2026.

The recommended strategy is:

Identify the additional assessment → identify the penalty decision → verify notification → challenge the underlying customs liability → independently review the penalty conditions → verify calculations → raise procedural and limitation defenses → protect objection deadlines → evaluate settlement where appropriate → prepare judicial proceedings if necessary.

1. Why Does Customs Issue Both Additional Duty and a Penalty?

An additional customs assessment generally seeks to recover an amount that Customs considers should originally have been paid.

The penalty serves a different function: it is an administrative sanction imposed because Customs considers the declaration to have violated the applicable customs rules.

For example, Customs may conclude:

Correct customs liability: TRY 1,000,000

Originally paid: TRY 600,000

Difference: TRY 400,000

Customs may then seek the TRY 400,000 difference and impose an administrative penalty under the applicable provision.

2. Additional Duty and Penalty Are Legally Distinct

This distinction is critical.

The company should ask two separate questions:

Was the additional customs liability legally correct?

and

Were the statutory requirements for the administrative penalty satisfied?

A company should not assume that because additional duty may be payable, every related penalty is automatically lawful.

3. Both Decisions Can Be Challenged

Where the procedural requirements are satisfied, the company may challenge both:

• The additional customs assessment;
• The administrative penalty.

The objection should clearly identify every decision being challenged.

4. Start With the Underlying Customs Assessment

In many cases, the penalty depends on the alleged customs difference.

Therefore, first investigate why Customs believes additional duty is payable.

Typical disputes involve:

• Tariff classification;
• Customs value;
• Origin;
• Preferential treatment;
• Anti-dumping duties;
• Additional customs duties;
• Quantity;
• Import exemptions.

5. If the Additional Assessment Falls, the Penalty May Also Be Affected

Suppose Customs alleges that the importer used the wrong tariff classification.

If the company’s declared classification is ultimately found to be correct, the alleged duty difference may disappear.

That can directly affect a penalty based on the same alleged duty loss.

This is why challenging only the penalty can be a serious strategic mistake.

6. The Penalty Must Still Be Reviewed Independently

Even if some additional customs duty is ultimately payable, the company should separately examine:

• Correct penalty provision;
• Statutory conditions;
• Calculation;
• Procedural requirements;
• Applicable historical legislation.

Do not concede the penalty merely because an additional amount may remain payable.

7. Customs Value Cases Can Produce Significant Penalties

One common example involves alleged undervaluation.

The Ministry of Trade’s customs-value guidance explains that where declared customs value is found lower than the value determined under the statutory valuation provisions, Article 234 may result in collection of the additional import taxes together with a penalty calculated by reference to the tax difference.

Accordingly, the first question should be whether Customs’ revised valuation is legally correct.

8. Review Every Component of Customs Value

Potential disputes may involve:

• Purchase price;
• Freight;
• Insurance;
• Royalties;
• Licence fees;
• Assists;
• Related-party pricing;
• Additional payments.

A successful valuation defense can affect both the assessment and related penalty.

9. Tariff Classification Must Be Technically Reviewed

If Customs changes the tariff code, prepare evidence concerning:

• Product composition;
• Function;
• Technical characteristics;
• Manufacturing process;
• Intended use.

Do not rely solely on the commercial product name.

10. One Classification Change Can Affect Several Liabilities

A new tariff code may alter:

• Customs duty;
• Additional customs duty;
• Anti-dumping liability;
• Other import measures.

Therefore, verify the complete financial effect of the classification decision.

11. Origin Findings Should Also Be Challenged Where Appropriate

Customs may deny preferential treatment or impose additional liabilities because it disputes the declared origin.

Preserve:

• Origin certificates;
• Supplier declarations;
• Manufacturer records;
• Production information.

The underlying origin finding should be challenged before accepting related penalties.

12. Anti-Dumping Cases Require Separate Product-Scope Analysis

Where additional liability concerns anti-dumping duties, determine whether the imported goods actually fell within the measure applicable on the import date.

Review:

• Product description;
• Tariff classification;
• Origin;
• Manufacturer;
• Historical measure.

Do not assume current trade-defense rules applied identically to older imports.

13. Verify the Historical Law

For older declarations, identify the legislation applicable when the customs obligation arose.

This may affect:

• Duty rate;
• Additional duty;
• Anti-dumping measure;
• Penalty calculation.

Historical assessments require historical legal analysis.

14. Check Whether the Assessment Is Time-Barred

For old imports, limitation should be examined immediately.

Determine:

• Date customs debt arose;
• Date of additional assessment;
• Effective notification date;
• Any statutory exception.

A limitation defense can potentially affect the underlying customs claim and should not be overlooked.

15. Obtain Both Formal Decisions

Do not rely on a customs broker’s summary.

Obtain:

• Additional assessment decision;
• Penalty decision;
• Audit or secondary-control findings;
• Calculation schedules;
• Notification records.

The defense should respond to the actual decisions.

16. Check Whether Duty and Penalty Were Properly Issued and Notified

Customs legislation contains procedural rules concerning tax-related penalties and their relationship with the underlying customs duties.

Official Ministry materials state that customs-duty-linked monetary penalties are generally decided, notified and paid together with the corresponding customs duties.

If the administration followed a materially different procedure, examine whether that creates a procedural defense.

17. Record Every Notification Date

Create a table:

Decision	Amount	Notification Date	Issue	Challenge
Additional Duty	Amount	Date	Classification	Review
Penalty	Amount	Date	Article 234	Review

Deadline control is essential.

18. Protect the Administrative Objection Period

The applicable objection mechanism under Customs Law No. 4458 should be assessed immediately after notification.

Do not allow internal meetings, negotiations or correspondence with the customs broker to consume the available challenge period.

19. Identify Both Decisions Expressly in the Objection

The objection should clearly state that the company challenges, where applicable:

the additional customs assessment

and

the related administrative penalty.

Avoid wording that could create uncertainty over the scope of the objection.

20. Use Separate Grounds for Each

A structured objection can state:

Additional Assessment

• Classification is incorrect;
• Customs value adjustment is unlawful;
• Origin finding is unsupported;
• Assessment is time-barred.

Penalty

• Underlying tax difference does not exist;
• Wrong penalty provision applied;
• Statutory conditions are not satisfied;
• Penalty calculation is incorrect.

This makes the defense significantly clearer.

21. Check the Mathematical Calculation

Never assume the administration’s calculation is automatically correct.

Verify:

• Customs value;
• Quantity;
• Exchange rate;
• Duty rate;
• Tax difference;
• Penalty multiplier.

Small errors can become significant in large imports.

22. Material Calculation Errors May Receive Different Treatment

The Ministry’s guidance on customs value notes that Article 234 contains different treatment for certain limited quantity differences and material calculation errors, rather than automatically applying the ordinary heavier penalty structure.

Therefore, determine precisely what type of declaration difference occurred.

23. Technical Disagreement Is Different From Factual Misstatement

A dispute concerning interpretation of a tariff heading is not necessarily the same as declaring an objectively incorrect quantity or invoice amount.

The factual nature of the alleged violation should be described accurately.

24. Do Not Make Unnecessary Admissions

Avoid statements such as:

“We knowingly underpaid customs tax.”

The actual issue may instead involve:

• Technical interpretation;
• Supplier information;
• Broker error;
• Valuation disagreement.

Responses should reflect the facts precisely.

25. Multiple Declarations Require a Decision Matrix

If Customs issues assessments for numerous declarations, prepare:

Declaration

Additional duty

Penalty

Legal basis

Notification

Defense

Deadline.

This prevents procedural mistakes.

26. One Decision May Cover Multiple Related Declarations

Official customs materials recognize that, where the subject and liable party are the same and there is a factual or legal connection, duties and penalties relating to multiple transactions or declarations may be included in one assessment and penalty decision.

Check carefully which declarations are covered by each decision.

27. Broker Error Should Be Investigated Separately

If the customs broker caused the disputed declaration, preserve:

• Instructions;
• Draft declarations;
• Product documents;
• Emails.

Potential broker responsibility does not automatically resolve the company’s dispute with Customs.

28. Supplier Responsibility May Also Exist

If additional duties resulted from incorrect:

• Origin;
• Invoice;
• Composition;
• Product description,

review contractual remedies against the foreign supplier.

29. Consider Whether Similar Historical Declarations Exist

A single additional assessment may reveal wider exposure.

Search historical imports involving the same:

• Product;
• Tariff code;
• Supplier;
• Origin;
• Valuation method.

Do this before further assessments arrive.

30. Review Current Imports Immediately

If the same customs treatment is still being used, review:

• Goods at port;
• Goods in transit;
• Future declarations.

The objective is to prevent additional exposure while preserving the historical defense.

31. Settlement May Cover Both Customs Receivables and Penalties

The Ministry’s customs settlement guidance states that qualifying customs receivables arising from differences identified by Customs, together with penalties covered by the relevant legislation, may fall within the settlement mechanism.

Whether settlement is strategically appropriate depends on the case.

32. Do Not Request Settlement Automatically

Before choosing settlement, assess:

• Strength of substantive defense;
• Limitation;
• Calculation errors;
• Amount of penalty;
• Future-import consequences.

If the underlying assessment is legally weak, cancellation may be more important than merely reducing the financial amount.

33. Understand the Consequence of Settlement

Official Ministry materials state that a settlement record is final and that matters agreed in the settlement cannot subsequently be litigated or challenged through complaint procedures.

Therefore, settlement should be an informed strategic choice.

34. Payment Strategy Should Be Coordinated With the Appeal

Large additional assessments can create cash-flow concerns.

Before payment, determine:

• Procedural consequences;
• Challenge strategy;
• Potential enforcement exposure.

Do not treat payment as purely an accounting decision.

35. Judicial Review May Be Required

If the administrative challenge is unsuccessful, the company should evaluate the appropriate judicial proceedings.

Prepare the potential court file early.

36. Technical Evidence Should Be Ready Before Litigation

Depending on the dispute, collect:

• Technical reports;
• Laboratory results;
• Manufacturer statements;
• Valuation agreements;
• Origin records.

Do not wait until the court stage to begin evidence collection.

37. 2026 Customs Audits Are Generating Significant Assessments

The Ministry reported that during the first eight months of 2026, 142,768 declarations underwent secondary review, and additional assessments and penalty decisions totaling TRY 8.3 billion were issued regarding 23,132 declarations involving 3,606 companies. Post-clearance company audits generated a further TRY 1.8 billion.

For foreign companies with repetitive import structures, one customs finding should therefore trigger an immediate broader compliance review.

38. Separate Cancellation Strategy From Reduction Strategy

The company may have several alternative objectives:

Cancel the additional duty and penalty entirely

or

cancel the penalty while contesting the duty

or

reduce the overall exposure through an available administrative mechanism.

These strategies should not be confused.

39. Avoid Double Recovery or Duplicate Penalties

If several penalty provisions are applied to the same underlying conduct, examine whether administrative-offense aggregation principles affect the cumulative sanctions.

This is separate from the question of whether Customs can recover the underlying unpaid duty.

40. Criminal Allegations Change the Risk Profile

If Customs also alleges conduct potentially falling within criminal customs legislation, administrative responses should be coordinated with the criminal defense.

Do not prepare the tax objection in isolation.

41. Foreign Companies Should Inform Headquarters Early

Prepare a concise exposure report showing:

Additional duty

Penalty

Declarations affected

Main legal issue

Limitation

Appeal deadline

Potential wider exposure.

This allows headquarters to make timely decisions.

42. Accounting Provisions Should Not Determine the Legal Defense

A company may create an accounting provision for a disputed customs liability.

That internal accounting decision does not itself determine whether the customs assessment is legally correct.

Keep accounting treatment and legal position distinct.

43. Build One Integrated Customs Defense File

Include:

• Decisions;
• Notification evidence;
• Declarations;
• Technical evidence;
• Contracts;
• Customs-value documents;
• Origin records;
• Calculation spreadsheet;
• Objection documents.

This is especially important where both duty and penalty are contested.

44. The Strongest Defense Attacks Each Component Separately

A comprehensive customs objection may argue:

No additional customs duty is legally due.

Alternatively:

Even if some additional duty is due, the amount is incorrectly calculated.

Additionally:

Even if some duty remains payable, the administrative penalty is unlawful or incorrectly calculated.

These arguments can coexist.

45. Immediate Strategy After Receiving Both Decisions

The recommended sequence is:

Obtain the additional assessment

→ obtain the penalty decision

→ record notification dates

→ identify the underlying customs issue

→ review tariff, value, origin or other substantive issue

→ check limitation

→ verify calculations

→ review the penalty independently

→ protect administrative objection rights

→ evaluate settlement only after assessing the merits

→ review similar historical imports

→ prepare judicial proceedings where necessary.

25-Point Additional Duty and Penalty Checklist

1. Obtain the additional assessment.
2. Obtain the penalty decision.
3. Record notification dates.
4. Identify the declarations involved.
5. Determine the legal basis of the additional duty.
6. Determine the penalty provision.
7. Review tariff classification.
8. Review customs value.
9. Review royalties.
10. Review origin.
11. Review preferential treatment.
12. Review anti-dumping exposure.
13. Verify historical legislation.
14. Check limitation.
15. Verify quantity.
16. Verify exchange rates.
17. Recalculate the additional duty.
18. Recalculate the penalty.
19. Review procedural defects.
20. Protect objection deadlines.
21. Review broker responsibility.
22. Review supplier responsibility.
23. Examine similar historical declarations.
24. Evaluate settlement where appropriate.
25. Prepare judicial strategy.

Frequently Asked Questions

1. Can both the additional customs duty and administrative penalty be challenged?

Yes. Where procedural requirements are satisfied, the company may challenge both the underlying customs assessment and the related administrative penalty.

2. Does challenging the tax automatically challenge the penalty?

The safest approach is to identify and challenge each relevant decision expressly rather than assuming that an objection to one automatically covers the other.

3. If the additional duty is cancelled, what happens to the penalty?

Where the penalty depends directly on the alleged duty difference, cancellation of the underlying assessment may materially affect the legal basis of the related penalty.

4. Can the penalty be challenged even if some additional duty is payable?

Yes. The statutory conditions and calculation of the administrative penalty should be analyzed independently.

5. Can Customs impose a penalty for undervaluation?

Potentially. Ministry guidance confirms that Article 234 provides for additional import taxes and a tax-difference-based penalty in qualifying customs-value underdeclaration cases.

6. Can old additional customs assessments be time-barred?

Potentially. Historical assessments should be reviewed under the applicable limitation framework and any statutory exceptions.

7. Can the company settle both the tax and penalty?

Qualifying customs receivables and penalties may fall within the customs settlement framework, subject to applicable requirements and procedural timing.

8. Should the company pay first and appeal later?

The payment and challenge strategy should be determined after reviewing the applicable procedural rules, enforcement risk and legal merits.

9. What if the customs broker made the declaration error?

Potential broker responsibility should be investigated separately. It does not automatically eliminate the customs assessment against the relevant liable party.

10. What is the biggest mistake after receiving both an additional assessment and a penalty?

Treating them as one issue and challenging only the total amount without separately attacking the underlying customs liability, the legal basis of the penalty and the calculation of each.

Client-Focused Legal Support for Additional Customs Assessments and Penalties in Turkey

Customs disputes involving both additional duties and penalties may concern:

Additional customs assessments

Administrative penalties

Tariff classification

Customs valuation

Royalties and licence fees

Origin disputes

Anti-dumping duties

Historical customs declarations

Customs settlement

and judicial proceedings.

Fırat Fesih Kaya Law Office assists foreign companies, multinational groups, manufacturers and importers facing additional customs assessments and administrative penalties in Turkey.

Lawyer Fırat Fesih Kaya provides legal assistance in challenging the underlying customs liability and related penalties, reviewing calculations and limitation issues, preparing administrative objections, evaluating settlement options and pursuing appropriate judicial remedies.

Phone: +90 312 434 22 22
Mobile: +90 532 769 22 22
Email: info@firatfesihkaya.av.tr
Address: Mevlana Boulevard No:221, Yıldırım Tower, Office No:148, 06520 Balgat, Çankaya, Ankara, Turkey