Customs Duty — Assessment, Valuation & Tariff Schedules

Every country maintains a national tariff schedule — a comprehensive document listing every possible product classification alongside its duty rate. In the US, this is the Harmonized Tariff Schedule (HTS) maintained by the USITC. In the EU, it's the TARIC database. In the UK, it's the UK Global Tariff.

When goods arrive at a port of entry, customs duty is assessed through a structured process:

1. Declaration: The importer (or their customs broker) files an import declaration specifying product description, HS code, country of origin, and declared value.
2. Classification Verification: Customs officers verify that the declared HS code matches the actual goods. If there's a discrepancy, customs may re-classify — often resulting in higher duty.
3. Valuation: Customs determines the transaction value (price actually paid) or applies alternative valuation methods if the transaction value isn't acceptable (WTO Customs Valuation Agreement).
4. Duty Calculation: The applicable duty rate from the tariff schedule is applied to the assessed customs value.
5. Payment & Release: Duties are paid (or secured by bond), and goods are released into domestic commerce. In most countries, duty must be paid before goods leave customs control.
6. Post-Clearance Audit: Customs authorities can audit declarations up to 5 years after importation in most jurisdictions, and reassess duty if errors are found.

The WTO Customs Valuation Agreement establishes 6 hierarchical methods for determining the value on which duty is assessed:

1. Transaction Value (Method 1): The price actually paid or payable. Used in ~95% of cases. This is the default and preferred method.
2. Transaction Value of Identical Goods (Method 2): Value based on identical goods sold for export to the same country around the same time.
3. Transaction Value of Similar Goods (Method 3): Same as Method 2 but using similar (not identical) goods.
4. Deductive Value (Method 4): Based on the resale price in the importing country, working backwards to deduct margins and costs.
5. Computed Value (Method 5): Based on the cost of production plus profit and general expenses.
6. Fall-back Method (Method 6): Flexible application of Methods 1-5, used when none of the above work. Cannot be based on arbitrary or fictitious values.

If you're unsure how your product should be classified, you can request a Binding Tariff Ruling (BTR) from customs authorities. This is an official, legally binding classification decision that customs must honor at the time of import.

• US: Request a CBP Ruling — free of charge, typically takes 30-90 days. Valid for cross-referencing throughout US ports.
• EU: Apply for a Binding Tariff Information (BTI) decision — valid for 3 years across all 27 EU member states.
• UK: Request an Advance Tariff Ruling (ATR) from HMRC — valid for 3 years.

When to request a ruling: For novel products, multi-component goods, products near chapter boundaries, or any item with a duty rate differential that materially impacts your landed cost. The ruling eliminates classification risk entirely.

Beyond standard tariff rates, customs authorities impose additional duties in specific circumstances:

If you believe customs has incorrectly classified, valued, or assessed your goods, you have the right to appeal:

• US: File a Protest (19 CFR §174) within 180 days of liquidation. If denied, appeal to the U.S. Court of International Trade.
• EU: Appeal to the national customs authority first, then to the relevant national court. The Court of Justice of the EU (CJEU) handles questions of EU customs law interpretation.
• UK: Request a departmental review or appeal directly to the First-tier Tribunal (Tax Chamber).

In all jurisdictions, you can pay the disputed duty under protest (securing release of your goods) while the appeal is pending. Interest is paid on any overpayment if the appeal succeeds.