An apparel importer in New York brought in 2,000 units of women’s cotton blouses from Bangladesh. The importer classified the blouses under HS code 6206.30.30, which carries a duty rate of 15.4%. A licensed customs broker reviewing the shipment identified that the blouses should have been classified under 6206.30.20 (a subcategory for blouses with specific construction features), which carries a rate of 8.4%. On a declared value of $86,000, the correct classification saved the importer $6,020 on a single shipment.
Multiply that across a year of imports, and the difference between correct and incorrect duty classification is the difference between a profitable product line and a marginal one.
Customs duties and import taxes are among the largest variable costs in international trade. For many products, the duty rate exceeds the freight cost. Yet importers frequently accept whatever duty they are assessed without understanding how duties are calculated, what exemptions may apply, or how classification decisions affect their bottom line.
This guide explains how US customs duties and import taxes work, how they are calculated, the key exemptions and programs that reduce costs, and how freight forwarders help importers navigate this complex system.
Customs duties are taxes imposed by a government on goods imported into the country. In the United States, customs duties are collected by US Customs and Border Protection (CBP) on behalf of the US Treasury.
Customs duties serve several purposes:
| Duty Type | How It Works | Example |
|---|---|---|
| Ad valorem | Percentage of the declared value | 5% of $100,000 = $5,000 |
| Specific | Fixed amount per unit of measure | $0.25 per kilogram |
| Compound | Combination of ad valorem + specific | 3% + $0.10 per kilogram |
| Anti dumping (AD) | Additional duty on goods sold below fair market value | Varies by product and country |
| Countervailing (CVD) | Additional duty to offset foreign government subsidies | Varies by product and country |
| Section 301 | Tariffs imposed in response to unfair trade practices | 7.5% to 25% on specified Chinese goods |
| Section 232 | Tariffs based on national security concerns | 25% on steel, 10% on aluminum |
Every imported product must be classified under the Harmonized Tariff Schedule of the United States (HTSUS). The HS code determines the applicable duty rate. The HTSUS contains over 17,000 distinct product classifications, and selecting the correct one requires detailed knowledge of the product’s composition, function, and construction.
Why classification matters: A product classified under one HS code might face a 0% duty rate, while the same product classified under an adjacent code faces 12%. Classification decisions are not arbitrary. They must be based on the actual characteristics of the goods, the General Rules of Interpretation (GRI), and CBP rulings.
US customs duties on ad valorem (percentage based) items are calculated on the transaction value of the goods. Transaction value is the price actually paid or payable for the goods when sold for export to the United States.
What is included in transaction value:
What is NOT included:
The country where the goods were manufactured or substantially transformed determines which duty rate applies. This is especially important for:
Basic duty calculation:
Duty = Declared Value × Duty Rate
Example: $200,000 shipment of furniture from Vietnam, classified under HTSUS 9403.60.80 (wooden furniture), duty rate 0% (under GSP or MFN depending on specific type).
Example with Section 301 tariffs: $200,000 shipment of electronics from China, MFN duty rate 3.9% + Section 301 tariff 25% = effective rate 28.9%. Duty = $200,000 × 28.9% = $57,800.
Beyond the basic duty, US imports are subject to additional fees:
| Fee | Rate | Applied To |
|---|---|---|
| Merchandise Processing Fee (MPF) | 0.3464% of value (min $31.67, max $614.35) | Most imports |
| Harbor Maintenance Fee (HMF) | 0.125% of value | Ocean imports only |
| Bond premium | Varies | Continuous or single entry bonds |
The United States has free trade agreements with 20 countries. Goods that qualify under these agreements enter at reduced or zero duty rates.
Major US FTAs:
To claim FTA preferential rates, importers must present a valid certificate of origin and the goods must meet the agreement’s rules of origin requirements.
Foreign Trade Zones are designated areas within the United States where goods can be imported, stored, assembled, manufactured, or re exported without paying customs duties until the goods enter US commerce. FTZ benefits include:
Goods imported temporarily for specific purposes (trade shows, testing, repair) can enter duty free under a Temporary Import Bond, provided they are re exported within one year.
Duty drawback allows importers to recover up to 99% of duties paid on imported goods that are subsequently exported. This applies to goods that are:
Many importers use the HS code provided by their overseas supplier without independent verification. Supplier classifications are frequently wrong because the supplier may not understand the nuances of US tariff classification. A qualified customs broker should independently verify every classification.
Importers leave billions of dollars in duty savings unclaimed every year because they do not know their goods qualify for FTA preferential rates, or because they do not obtain the required certificates of origin from their suppliers.
Under declaring the value of goods to reduce duties is customs fraud. Over declaring (by including costs that should be excluded, like inland freight) results in overpaying duties. Both are problems that proper valuation review prevents.
AD/CVD rates can add 20% to 300%+ to the effective duty rate on specific products from specific countries. Importers who do not check for AD/CVD orders before sourcing from a new country can face devastating unexpected costs.
Companies that import components, add value, and then export finished products may be eligible for duty drawback but never file claims. For manufacturers with significant import duty expenses and export volumes, drawback can recover hundreds of thousands of dollars annually.
Freight forwarders with customs brokerage capabilities (or strong customs broker partnerships) add significant value to the import process:
Accurate classification. Experienced customs brokers classify products correctly the first time, avoiding overpayment and compliance risk. They stay current on tariff changes, ruling modifications, and classification precedents.
FTA qualification. Forwarders advise importers on FTA eligibility and coordinate with overseas suppliers to obtain the required origin documentation.
Duty optimization. Beyond classification, forwarders identify opportunities for FTZ usage, drawback programs, TIB entries, and other duty reduction strategies.
Compliance protection. Proper classification, valuation, and origin determination protect importers from CBP audits, penalties, and enforcement actions. GoFreight’s platform helps forwarders maintain the detailed shipment documentation that supports duty claims and audit defense.
The duty rate for any product is found in the Harmonized Tariff Schedule of the United States (HTSUS), available for free on the US International Trade Commission website. Search by product description or HS code. The HTSUS shows the general (MFN) duty rate, special (FTA preferential) rates, and Column 2 rates (for non MFN countries). For products subject to additional tariffs (Section 301, Section 232, AD/CVD), check the relevant Federal Register notices and CBP guidance. A licensed customs broker can provide definitive classification and rate determination for your specific products.
In the United States, the term “customs duty” refers to the tariff assessed on imported goods based on their HS code classification and value. There is no separate federal “import tax” beyond customs duties and the standard processing fees (MPF, HMF). However, imported goods are subject to the same state and local sales taxes as domestically produced goods when they are sold to consumers. In some other countries, import taxes such as Value Added Tax (VAT) or Goods and Services Tax (GST) are assessed at the point of importation in addition to customs duties.
Yes. If you discover that you overpaid customs duties due to incorrect classification, incorrect valuation, or failure to claim FTA preferential rates, you can file a post entry amendment or protest with CBP to recover the overpayment. The timeframe for filing is generally within 180 days of liquidation for protests and up to one year for voluntary corrections. For drawback claims (recovering duties on goods that are subsequently exported), the filing window is up to five years. The amounts recovered can be substantial, making periodic duty audits a worthwhile exercise.
Incorrect classification can result in underpayment or overpayment of duties. If you underpay, CBP may issue a penalty ranging from 20% to 40% of the unpaid duties for negligence, or up to four times the unpaid duties for fraud. You will also owe the original underpaid duty plus interest. If you overpay, you can file for a refund, but you only recover the overpayment for entries within the allowable filing period. Repeated classification errors may trigger a focused assessment (audit) by CBP, which examines your entire import history for compliance issues.
Yes. Many products enter the United States duty free under the standard MFN (Most Favored Nation) tariff schedule, meaning no trade agreement is needed. Examples include many raw materials, certain industrial chemicals, and specific technology products covered by the Information Technology Agreement (ITA). The HTSUS shows “Free” as the general duty rate for these products. However, even duty free goods may still be subject to additional tariffs (Section 301, Section 232) depending on the country of origin and product category.