📅 July 2026 Update — Critical Changes: (1) Section 301 China tariffs in full effect: Lists 1–3 at 25%, List 4A at 7.5%, sector rates 50–100% (EVs, semiconductors, solar). (2) IEEPA-based tariffs (reciprocal/fentanyl) struck down by Supreme Court early 2026 — no longer in effect. Recalculate if you factored these in. (3) New USTR forced-labor investigation proposed 12.5% additional on Chinese goods — hearing July 7, 2026, final action imminent. (4) Second four-year review of core Section 301 tariffs began May 2026.
What Are Customs Duties and Tariffs?
Customs duties and tariffs are fees that governments impose on imported or exported goods. They serve multiple purposes: protecting domestic industries from foreign competition, generating government revenue, and enforcing trade policy objectives. The applicable rate depends on the HTS (Harmonized Tariff Schedule) classification of the goods, their country of origin, and any applicable trade agreements or special tariff measures.
Duties are generally calculated as a percentage of the customs value (ad valorem), a fixed amount per unit (specific), or a combination of both (compound). Understanding which duties apply — and at what rate — is fundamental to accurate import cost modeling.
Types of Customs Duties
Ad Valorem Duties
The most common type — calculated as a percentage of the customs value (transaction value including CIF). Example: a 10% ad valorem duty on a $50,000 shipment = $5,000 in duties. Most standard MFN (Most Favored Nation) duties are ad valorem.
Specific Duties
A fixed amount per unit, weight, or volume — not based on value. Example: $0.20 per kilogram. Common for agricultural products like sugar and tobacco.
Compound Duties
A combination of ad valorem and specific duties. Example: 5% plus $2.50 per unit. Used for products like footwear and some textiles.
Tariff-Rate Quotas (TRQs)
A specific quantity of goods can be imported at a lower duty rate. Imports above the quota face a higher ‘over-quota’ rate. Common for dairy, beef, and agricultural products under U.S. trade agreements.
Special Tariff Measures — 2025/2026 Update
The standard MFN tariff schedule is just one layer. In 2025–2026, U.S. importers must also account for:
Section 301 Tariffs (China):
- Lists 1–3: 25% additional duty (machinery, electronics, chemicals, consumer goods)
- List 4A: 7.5% additional duty
- Sector-specific rates: EVs 100%, semiconductors 50%, solar cells 50%, lithium-ion batteries 25%
- Exclusions for certain products extended through November 10, 2026
- New forced-labor Section 301 investigation: 12.5% proposed; final action anticipated July–August 2026
How Customs Duties Are Calculated
Step 1 — Classify the goods (10-digit HTS code): The HTS code determines the base MFN duty rate. Misclassification is one of the most common — and costly — customs compliance errors.
Step 2 — Determine country of origin: Country of origin determines which preferential rates (USMCA, free trade agreements) or special tariff measures (Section 301, ADD/CVD) apply.
Step 3 — Calculate customs value: CBP uses transaction value (what you actually paid) as the primary valuation method. Add freight and insurance costs to CIF value for the calculation base.
Step 4 — Apply all applicable duty layers: MFN rate + Section 301 (if applicable) + ADD/CVD (if applicable).
Step 5 — Add government fees: Merchandise Processing Fee (MPF): 0.3464% of customs value (min $31.67, max $614.35 per entry). Harbor Maintenance Fee (HMF): 0.125% of cargo value for ocean imports.
The Role of Customs Authorities (CBP)
CBP is responsible for reviewing import entries, enforcing the correct HTS classification, inspecting goods, and collecting duties, taxes, and fees. CBP has broad authority to re-liquidate entries (adjust the duty amount) within four years of the original filing. Post-entry audits (Focused Assessment and Quick Response Audits) are increasingly common in the 2025–2026 enforcement environment.
CBP can seize goods, issue penalty notices (including Prior Disclosure protection for self-reporting errors), and refer egregious violations to federal prosecutors. Accurate classification and valuation — with documented methodology — is your best protection.
Know Your Tariff Rate Before You Import
FreightClear.com helps importers calculate accurate duty obligations — including Section 301 tariffs, ADD/CVD, MPF, and all applicable fees. Use our HTS code finder or speak with a licensed customs broker before your next shipment.
