ACE will now reject use of exemption HTS 9903.03.15 for Section 338 lines lacking a corresponding dutiable Chapter 99 HTS.

CBP has issued a correction to prior guidance via CSMS #69941677, updating the applicable Harmonized Tariff Schedule (HTS) number to 9903.03.15 in the ACE CATAIR Entry Summary Error Dictionary V53. The key operational change for trade compliance and customs brokers is the introduction of ACE error F884: “EXEMPT HTS NOT ALLOWED FOR SECTION 338.” Under this rule, ACE will not allow the use of exemption HTS 9903.03.15 on a Section 338 (S338) line if there is no appropriate dutiable Chapter 99 HTS reported on that same line.

This does not change any underlying duty rates or create new trade remedies, but it directly affects how duty relief or exemptions are claimed and how entries are structured. In practice, when claiming an exemption via 9903.03.15 for S338, brokers must first or concurrently report the corresponding dutiable Chapter 99 HTS code on the same line. If 9903.03.15 is transmitted without that dutiable CH99 code, ACE will generate error F884 and reject or require correction of the entry summary.

The update has been deployed to both CERT and PROD environments as of August 26, 2026, meaning it is already in effect for live filings. Customs brokers and importers should immediately review and adjust their entry templates, ABI mapping, and internal filing instructions for any products subject to Section 338 measures where 9903.03.15 is used. Entry software should be configured to validate that any S338 line using 9903.03.15 also includes the appropriate dutiable Chapter 99 HTS, preventing F884 errors before transmission. Staff responsible for classification and entry preparation should be briefed on this requirement so that exemption claims under 9903.03.15 are properly paired with the relevant dutiable CH99 code and do not delay cargo release or liquidation due to ACE rejections.