9903.05.71 Korea Section 301 Forced Labor: 12.5% Duty

Key Points

• HTS 9903.05.71 imposes a 12.5 percent additional ad valorem duty on all products of the Republic of Korea (KR), effective July 24, 2026, with no announced end date.
• This is a Section 301 forced labor action under U.S. note 52, authorized by the USTR FLIP final action dated July 23, 2026.
• The duty is MFN-capped: the combined total of the normal column 1 rate plus this additional 12.5 percent cannot exceed 12.5 percent ad valorem, meaning if a product already carries a column 1 rate, the additional duty is reduced so the sum does not surpass 12.5 percent.
• Every chapter 1-97 product originating in the Republic of Korea is in scope, with no product exclusions announced in the facts as of September 14, 2026.
• CBP published implementing guidance in CSMS 69326983; importers should confirm current status in the live HTSUS and with their broker.

On this page

1. What 9903.05.71 is and who must care
2. Legal authority and program background
3. Affected products and country scope
4. Rate, MFN cap, and how stacking works
5. How 9903.05.71 appears on a customs entry
6. What importers should do
7. Key references

The links in this article go to primary documents: the USTR final action, CBP's CSMS guidance, and the official tariff schedule pages themselves. Read the source.

HTS 9903.05.71 is a Chapter 99 overlay code that adds 12.5 percent in additional duties to all goods of the Republic of Korea entering the United States under any chapter 1-97 classification. It took effect on July 24, 2026, under the Section 301 forced labor program governed by U.S. note 52 to Chapter 99. Any importer whose entry covers merchandise originating in South Korea must include this code alongside the regular classification line or face underpayment of duties.

What 9903.05.71 is and who must care

As of September 14, 2026, HTS 9903.05.71 reads: Products of Korea (Republic of), Section 301 forced-labor action, U.S. note 52: +12.5% ad valorem (MFN-capped: column 1 + this duty = 12.5%).

Any U.S. importer of record bringing in merchandise that originates in the Republic of Korea (country code KR) is directly affected. Customs brokers must add this secondary Chapter 99 line to every entry summary covering Korean-origin goods. Trade attorneys reviewing classification or protest strategies need to understand both the rate and the MFN cap before advising clients.

Note carefully: codes 9903.05.01 through 9903.05.09 are a separate Section 301 Brazil program, not this one. The Section 301 forced labor country codes run from 9903.05.20 through 9903.05.84. Do not confuse the two series.

Legal authority and program background

The duty is imposed under Section 301 of the Trade Act of 1974, applied here specifically to address forced labor practices. The governing instrument is the USTR FLIP final action dated July 23, 2026, which triggered the July 24, 2026 effective date. The structural rules for all country codes in this program, including product scope and the MFN cap formula, are set out in U.S. note 52 to Chapter 99 of the Harmonized Tariff Schedule of the United States.

CBP operationalized the action through CSMS message 69326983. That message is the primary CBP-level instruction to trade; you can search for it at cbp.gov. For the statutory text of Section 301, see 19 U.S.C. 2411 at law.cornell.edu.

For context on how similar country-specific codes in the same program work, see our articles on 9903.05.67 Saudi Arabia and 9903.05.64 Philippines, which share the same legal framework.

Affected products and country scope

The scope under U.S. note 52(a) is intentionally broad:

• Country: Republic of Korea (KR) only
• Products: All articles classified in chapters 1 through 97 of the HTSUS
• Effective window: July 24, 2026, onward, with no announced end date

There are no product-level carve-outs or exclusions reflected in the facts as of September 14, 2026. Because the scope covers all chapter 1-97 products, importers of consumer electronics, machinery, textiles, chemicals, automotive components, and every other commodity category sourced from Korea must apply this code. If you believe a specific product may fall outside scope, confirm the current text of U.S. note 52 in the live HTSUS at hts.usitc.gov or consult your broker.

Rate, MFN cap, and how stacking works

The 12.5 percent additional duty

The additional duty rate is 12.5 percent ad valorem, applied on top of whatever column 1 (MFN/normal trade relations) rate the underlying chapter 1-97 classification carries. This rate has been in place since July 24, 2026, and no end date has been announced.

The MFN cap and what it means in practice

The MFN cap is a critical feature: the sum of the column 1 duty rate plus the 9903.05.71 additional duty cannot exceed 12.5 percent. In practical terms:

• If a product's column 1 rate is 0 percent (duty-free), the full 12.5 percent additional duty applies, bringing total duty to 12.5 percent.
• If a product's column 1 rate is, for example, 5 percent, the additional duty under 9903.05.71 is reduced to 7.5 percent so that the combined rate equals 12.5 percent.
• If a product's column 1 rate is already 12.5 percent or higher, the additional duty under 9903.05.71 is reduced to zero, and U.S. note 52 effectively adds nothing further for that line item.

This cap means importers of products with higher existing MFN rates may see little or no additional duty burden from this code. Run your specific classification through the current rate schedule at hts.usitc.gov or use our duty calculator to model the impact for your product.

Stacking with other Chapter 99 duties

If a Korean-origin product is also subject to other Chapter 99 duties, such as Section 232 steel or aluminum tariffs or other Section 301 actions, each applicable Chapter 99 code is entered as a separate line on the entry summary. The 9903.05.71 line is additive with other Chapter 99 provisions unless a specific note states otherwise. The facts block is silent on explicit stacking rules for this code beyond the MFN cap described above; confirm with your broker or the current HTSUS text how additional Chapter 99 overlays interact for your specific product.

How 9903.05.71 appears on a customs entry

Chapter 99 codes never stand alone. On CBP Form 3461 (entry/immediate delivery) and the entry summary (CBP Form 7501), importers and brokers must list:

1. The primary chapter 1-97 classification (for example, a 10-digit HTS number for the specific product), with the applicable column 1 rate.
2. 9903.05.71 as a secondary classification line on the same entry, carrying the applicable additional duty calculated under the MFN cap.

The country of origin declared on the entry must be Korea (KR) for this code to be triggered. If your goods transit through a third country but originate in Korea, origin rules under CBP regulations still govern; the declared origin drives the applicable Chapter 99 overlay. For more on entry procedures, see our article on CBP Form 3461.

If CBP questions the classification or origin, it may issue a CBP Form 28 (Request for Information) or a CBP Form 29 (Notice of Action). Responding accurately and promptly is essential to avoid penalty exposure.

What importers should do

• Audit open and upcoming entries: For any Korean-origin goods entered on or after July 24, 2026, verify that 9903.05.71 was declared and that the additional duty was calculated correctly under the MFN cap formula. Entries that omitted this code may require a post-summary correction.
• Recalculate landed costs: Use the MFN cap formula to determine the actual incremental duty burden for each product classification. Duty-free or low-rate products bear the full 12.5 percent additional duty; high-rate products may see little or no increase. Revisit purchasing decisions and supplier pricing accordingly using our duty calculator.
• Monitor for changes: No end date has been announced, but Section 301 actions can be modified or terminated. Subscribe to USTR and CBP CSMS updates, and periodically recheck U.S. note 52 in the live HTSUS at hts.usitc.gov for any amendments.
• Consider a binding ruling if scope is uncertain: If you have questions about whether a specific product qualifies as of Korean origin or falls within U.S. note 52 scope, a CBP binding ruling provides written certainty before goods arrive.

Key references

• Harmonized Tariff Schedule of the United States (hts.usitc.gov): Live text of 9903.05.71 and U.S. note 52 to Chapter 99.
• CBP.gov / CSMS 69326983: CBP implementing guidance for the Section 301 forced labor Korea action; search CSMS 69326983 on the CBP trade portal.
• USTR.gov: USTR FLIP final action dated July 23, 2026, authorizing the Korea Section 301 forced labor duty.
• Federal Register (federalregister.gov): Official publication of the final action and any subsequent modifications.
• 19 U.S.C. 2411, Section 301 of the Trade Act of 1974 (law.cornell.edu): Statutory authority for the program.
• 2026 Tariff Code Overview (CustomsGenius): Summary of major Chapter 99 developments effective in 2026.