1. Determine the HTS Code First: Wire Harnesses Usually Fall Under Heading 8544
Energy storage wire harnesses are generally classified under Chapter 8544 of the Harmonized Tariff Schedule of the United States (HTSUS), “Insulated wire, cable…”: those with connectors typically fall under 8544.42; those without connectors under 8544.49; ignition and similar wiring sets for vehicles, aircraft, or ships under 8544.30; and those rated for voltages exceeding 1,000 volts under 8544.60. While the first six digits of the Chinese HS code and the US HTS code for the same product are identical, the subsequent digits differ;
therefore, the tariff rate must be checked using the US code.
The official US tariff lookup portal is the US International Trade Commission website (hts.usitc.gov); simply enter the HTS code or the English product name to find the Most-Favored-Nation (MFN) rate listed in the “General” column.
II. Structure of Layered Tariffs on Chinese Exports to the US
Chinese goods exported to the US are currently subject to a three-tiered tariff structure: the first tier is the Most-Favored-Nation (MFN) base rate (for wire harness products under HS code 8544, this generally falls between 2% and 5%); the second tier consists of the “old” Section 301 tariffs—additional duties of 7.5% to 25% imposed on over $200 billion worth of Chinese goods during the Trump administration; and the third tier comprises the “new” Section 301 tariffs. Effective July 24, 2026, the Office of the United States Trade Representative (USTR) imposed these new Section 301 tariffs on 60 economies (including mainland China)—citing allegations of “forced labor”—to replace the expiring 10% tariff under Section 122; mainland China is subject to the 12.5% rate tier.
According to a calculation method released by the Sichuan Department of Commerce in September 2026, the new Section 301 tariffs are applied cumulatively with the old Section 301 tariffs. For instance, if a product has an MFN rate of 3% and an old Section 301 surcharge of 25%, the addition of the new 12.5% Section 301 tariff results in a combined tariff rate of approximately 40.5%.
III.
New Variables Since 2026
First, the new Section 301 tariffs include provisions for exemptions: products subject to Section 232 tariffs and those involving raw material shortages—among five specific categories—are exempt from the new Section 301 tariffs; therefore, it is necessary to verify the exemption list on an item-by-item basis.
Secondly, the expansion of Section 232 tariffs: The U.S. Department of Commerce issued a notice seeking public comment in August 2026, proposing to include copper conductor cables (covering HTS codes such as 8544.49.2000, 8544.49.3040, 8544.49.3080, and 8544.60.4000) within the scope of Section 232 tariffs applicable to steel, aluminum, and copper. The proposal suggests an additional 25% levy based on the customs value, with industry expectations pointing to a potential effective date around the fourth quarter. Once included, these products would be exempted from Section 301 tariffs and instead subject to the sum of the Most-Favored-Nation (MFN) rate and the Section 232 rate.
Thirdly, anti-dumping and countervailing duties (AD/CVD): If products are subject to AD/CVD investigations, these duties must be added on top of the aforementioned rates.
Fourthly, Section 301 tariff rates for energy storage-related battery categories have been raised: non-automotive lithium-ion batteries are subject to an additional 25% levy starting January 1, 2026. Additionally, small packages valued at $800 or less are subject to a 54% *ad valorem* duty or a specific duty of $100 per item, a calculation method that differs from that used for bulk cargo.
IV.
A Cost Calculation
Assume an energy storage wiring harness product carries an MFN tariff rate of 3% under the relevant U.S. HTS code and falls into the 25% tier of the original Section 301 list; with the addition of the new 12.5% Section 301 tariff, the combined tariff rate would be approximately 40.5%. However, if the product is a copper conductor wiring harness and the Section 232 expansion takes effect, the rate might shift to the MFN rate (3%) plus the Section 232 rate (25%)—totaling approximately 28%—without the additional Section 301 levy.
As the tariff rates for the same product vary significantly depending on the policy combination, it is essential to verify details against official sources and the latest announcements before quoting prices.
V. Practical Recommendations
Exporting enterprises are advised to: look up the “General” column (Most-Favored-Nation rate) for each US HTS code on hts.usitc.gov prior to shipment and verify any additional tariffs under Section 301 or 232 associated with Chapter 99 codes; continuously monitor the US Department of Commerce’s progress on expanding the scope of Section 232 measures and any new Section 301 exclusion lists; maintain and update a “Product–Code–Tariff Rate” ledger in line with policy changes; proactively assess the potential impact of Section 232 measures and prepare contingency plans for high-copper-content wire harnesses;
and, where necessary, mitigate tariff costs through adjustments to rules of origin compliance and supply chain reconfiguration.
Conclusion
Tariffs on energy storage wire harnesses exported to the US depend on HTS code classification and the specific mix of applicable policies; there is no single, uniform tariff rate.
Relying on official lookup results, performing dynamic calculations based on policy milestones, and integrating these calculations into the quotation process are essential practices for managing the costs and risks associated with US exports.
