9903.91.04 Explained: Section 301 China Four-Year Review, 25% Duty

Key Points

• HTS 9903.91.04 is a Chapter 99 Section 301 code that applied an additional 25% duty on top of the normal column-1 rate for certain Chinese-origin goods entered on or after January 1, 2025 and before January 1, 2026.
• The only product subheading covered was 6307.90.9870 (other made-up textile articles), and that window has now closed: the code is not in force for entries made on or after January 1, 2026.
• If you have unliquidated entries from January 1, 2025 through December 31, 2025 covering goods under 6307.90.9870 from China, 9903.91.04 should appear as a secondary line on those entries alongside the chapter 1-97 classification.
• No refund or retroactive relief under this code is established by the facts available as of October 12, 2026; confirm current posture with CBP or a licensed broker.
• This code is part of the Section 301 four-year-review escalation series under U.S. note 31 to Chapter 99, distinct from the original List 1-4 codes under 9903.88.

On this page

1. What 9903.91.04 is and where it fits in the Section 301 framework
2. Affected products and HTS coverage
3. The duty rate and how it stacks
4. Effective window and current status
5. How the code appears on a CBP entry
6. Interaction with other tariff provisions
7. What importers should do
8. Key references

HTS 9903.91.04 imposed an additional 25% Section 301 duty on articles from China classified under subheading 6307.90.9870, applicable only to entries made on or after January 1, 2025 and before January 1, 2026. The window is closed as of the facts date of October 12, 2026. Importers reviewing entries from that calendar year, and their brokers, are the primary audience for this article.

The links in this article go to the primary documents: the official Harmonized Tariff Schedule, CBP guidance pages, and the Federal Register. Read the source.

What 9903.91.04 is and where it fits in the Section 301 framework

The United States has maintained a layered set of Section 301 additional duties on Chinese-origin goods since the original List 1 actions. The initial tranches were assigned codes in the 9903.88 series. Following a statutory four-year review process, a separate escalation series was created under 9903.91 and 9903.92, governed by U.S. note 31 to Chapter 99 of the Harmonized Tariff Schedule.

9903.91.04 belongs to that four-year-review escalation series. Its official heading text reads: "Effective with respect to entries on or after January 1, 2025, and before January 1, 2026, articles the product of China, as provided for in subdivision (e) of U.S. note 31 to this subchapter." The authority tying this code to a specific product list is subdivision (e) of U.S. note 31. If you need the full text of that note, consult the official HTSUS at hts.usitc.gov.

For context on a closely related four-year-review code in the same series, see our article on 9903.91.01. For background on the original List 4 codes that preceded this escalation, see our articles on 9903.88.03 and 9903.88.04.

Affected products and HTS coverage

Exactly one chapter 1-97 subheading was covered by 9903.91.04:

• 6307.90.9870 - a residual basket provision within the "other made-up articles" heading of Chapter 63 (textiles), covering miscellaneous textile articles not elsewhere classified.

The scope is narrow and specific. If your goods classify elsewhere in 6307 or in an adjacent textile heading, this code does not apply. Confirm the correct eight- or ten-digit classification against the current HTSUS, since a misclassification at the chapter 1-97 level also changes which Chapter 99 overlay codes apply.

The duty rate and how it stacks

The HTSUS general-column rate for 9903.91.04 is: the duty provided in the applicable subheading + 25%. That means the 25% Section 301 additional duty is additive, not substitutive. An entry of goods under 6307.90.9870 from China during the window paid:

• The normal chapter 1-97 column-1 general rate for 6307.90.9870, plus
• 25% ad valorem under 9903.91.04.

Both amounts are calculated on the customs value of the merchandise. The 25% applies to the same dutiable value as the underlying rate, not on top of the already-calculated normal duty.

Effective window and current status

The effective window was January 1, 2025 through January 1, 2026 (that is, entries on or after January 1, 2025 and before January 1, 2026). As of October 12, 2026, that window is closed. No entries made on or after January 1, 2026 should carry 9903.91.04.

There is one covered rule in the facts for this code, and it ended on January 1, 2026. Zero rules under this code are in force today. If a post-January 1, 2026 entry for goods from China under 6307.90.9870 was filed with 9903.91.04, that may represent a classification error worth reviewing.

How the code appears on a CBP entry

Chapter 99 Section 301 codes ride as a secondary tariff line alongside the primary chapter 1-97 classification. On a CBP entry summary (Form 7501), a compliant filing during the window would show two lines for the same merchandise:

• Line 1: 6307.90.9870 with the applicable column-1 rate and dutiable value.
• Line 2: 9903.91.04 with the 25% additional duty reported against the same value.

CBP's Automated Commercial Environment (ACE) requires the Chapter 99 code to be present for the additional duty to be assessed correctly. If the secondary line was omitted on a liquidated entry from the 2025 window, CBP may issue a bill; conversely, if the line was added erroneously outside the window, a protest or post-summary correction may be warranted. Check the liquidation status of affected entries through ACE or your broker.

Interaction with other tariff provisions

Section 301 additional duties generally stack with other applicable duties. Consider whether the following also applied to your entries during the window:

• Section 232 duties on steel or aluminum derivatives, if the goods contain those inputs. See our articles on 9903.85.07 for derivative aluminum context.
• Antidumping or countervailing duty orders on textile articles from China. The facts block for this code is silent on any AD/CVD overlap; confirm with a broker whether any such orders cover 6307.90.9870.
• Other Section 301 codes that may have applied to the same goods under earlier or parallel tranches. The four-year-review codes in the 9903.91 series sit alongside, not in replacement of, the original 9903.88 series; the HTSUS and U.S. note 31 govern which code controls for a given entry date.

For a broader look at how tariff codes interact in 2026, see our 2026 tariff code overview.

What importers should do

• Audit 2025 entries for 6307.90.9870 from China. Confirm that 9903.91.04 appears as a secondary line on every entry with a date on or after January 1, 2025 and before January 1, 2026. Missing lines may result in underpayment; erroneous lines on entries outside the window may mean overpayment.
• Check liquidation status. Unliquidated entries from the window are still subject to CBP review. Entries that have liquidated may require a protest within the applicable timeframe if a correction is needed. See our article on the protest-to-CIT timeline for procedural context.
• Verify the post-January 1, 2026 classification. Now that the 9903.91.04 window is closed, confirm which Chapter 99 code, if any, applies to current entries of 6307.90.9870 from China. Confirm with a licensed broker or the current HTSUS, as the facts block does not identify a successor code.
• Document your classification rationale. For goods that straddle trade programs or have borderline chapter 1-97 classifications, maintain a written classification opinion for each affected SKU and retain it with the entry records.

Key references

• Harmonized Tariff Schedule of the United States (hts.usitc.gov) - Official HTSUS including Chapter 99, U.S. note 31, and subheading 9903.91.04.
• U.S. Customs and Border Protection (cbp.gov) - Entry filing requirements, ACE guidance, and CSMS messages on Section 301 duty collection.
• Federal Register (federalregister.gov) - Notices and rules establishing and modifying Section 301 four-year-review escalation rates.
• White House (whitehouse.gov) - Presidential proclamations and executive orders related to Section 301 trade actions.
• 19 U.S.C. Section 2411 (law.cornell.edu) - The statutory authority underlying Section 301 trade actions.