The current effective US tariff on most Chinese consumer goods is approximately 35% — 10% Section 122 plus 25% Section 301 — and that 10% layer expires on July 24, 2026. Any duty calculator hardcoding that rate will return incorrect landed costs in 127 days. Here's the full stack your system needs to model.
The Four-Layer Tariff Architecture
US tariffs on Chinese imports in 2026 are additive, not flat. A single HTS code can trigger four separate duty assessments, each governed by distinct legal authority. Your API must sum them correctly:
Layer 1: Base MFN duty. The product-specific Most Favored Nation rate from HTSUS. Range: 0% to 32%. Consumer electronics under the Information Technology Agreement carry 0% MFN; apparel runs 16–32%; general consumer goods typically 3–10%.
Layer 2: Section 122 surcharge. A flat 10% tariff effective February 24, 2026, applied globally with limited exemptions for energy, pharmaceuticals, and certain electronics. This layer has a statutory sunset: July 24, 2026. Your rate cache must treat this as a time-bound parameter.
Layer 3: Section 301 surcharge. Additional duties on Chinese-origin goods imposed under the Trade Act of 1974. Lists 1–3 carry 25%, List 4A carries 7.5%. Sector-specific rates are higher: EVs at 100%, semiconductors at 50%, solar cells at 50%, batteries at 25%. This layer was unaffected by the February 2026 SCOTUS ruling and remains in force indefinitely.
Layer 4: Section 232 duties. Steel and aluminum tariffs raised to 50% on February 1, 2026, with no country exemptions. Also covers copper, semiconductors, and certain lumber. For Chinese-origin goods, this stacks on top of Section 301, subject to anti-stacking rules from the April 29, 2025 executive order.
De Minimis Elimination: No More $800 Exemption
The $800 de minimis exemption was eliminated for China and Hong Kong on May 2, 2025, and extended to all origins on August 29, 2025. Every parcel — including Shein, Temu, and direct-to-consumer e-commerce shipments — now requires formal customs entry with full duty payment. Systems that previously bypassed duty calculation for low-value shipments must now process every transaction through the full four-layer stack.
Implementation note: If your API returns a de minimis flag for China-origin goods, that logic is 10 months stale. Remove the exemption path for CN/HK origin codes entirely.
Section 232 Steel/Aluminum at 50%
Section 232 duties on steel and aluminum increased from 25% to 50% on February 1, 2026, with no country exemptions remaining. For Chinese-origin steel products, this 50% rate stacks with the 25% Section 301 List 1 rate, creating a combined surcharge of 75% before MFN and Section 122 are applied. Your calculator must handle the anti-stacking rules specified in the April 29, 2025 executive order to avoid double-counting on covered products.
Warning: The Section 301 excess-capacity investigation launched March 11, 2026 could raise Chinese electronics rates by another 10 percentage points before year-end. Hard-coded rates will drift further from reality.
The July 24, 2026 Cliff
Section 122's 10% global tariff expires on July 24, 2026. What replaces it — if anything — depends on Congressional action and ongoing negotiations. Your duty calculator needs this date as a configurable parameter, not embedded logic. The swing in either direction is 5–10 percentage points on landed cost calculations.
For a $200,000 CIF annual import program, the Section 122 expiration alone represents a $20,000 variance. Systems returning stale rates after July 24 will generate incorrect duty estimates on every Chinese-origin transaction until manually corrected.
Building the Calculator: Required Parameters
A compliant 2026 China duty calculator must expose these as configurable inputs:
- HTS code — drives MFN rate lookup and Section 301 List assignment
- Section 301 List — List 1-3 (25%), List 4A (7.5%), or sector-specific (EV 100%, semiconductor 50%, solar 50%, battery 25%)
- Section 122 rate — currently 10%, expires July 24, 2026
- Section 232 applicability — 50% for steel/aluminum, with anti-stacking logic
- Effective date — must support date-range queries for historical and projected calculations
The formula is additive: Total Duty = MFN + Section 122 + Section 301 + Section 232, with anti-stacking rules applied where specified.
What to Model Before July 24
Run your 2026 import program through both scenarios: Section 122 at 10% and Section 122 at 0%. The March 11, 2026 Section 301 investigation targeting Chinese "excess capacity" introduces additional upside risk. Your compliance engineering team should treat current rates as a floor, not a ceiling, for planning purposes.