CSMS 63791838·Operational·January 17, 2025·View on csms.cbp.gov ↗

UPDATE: Section 321 Warning (Release 2) Set to Deploy January 18

Plain-English explanation

CSMS 63791838 is a U.S. Customs and Border Protection (CBP) Cargo Systems Messaging Service bulletin (operational), published on January 17, 2025. It carries the official CBP guidance brokers and importers must follow for the topic — "UPDATE: Section 321 Warning (Release 2) Set to Deploy January 18". CSMS messages are the operational layer between Commerce determinations and at-the-border collections: when Commerce publishes a new rate, scope ruling, or instruction, CBP turns it into a CSMS that ACE/ACS systems and brokers act on.

Message body

Full text as published by U.S. Customs and Border Protection

CSMS # 63791838 - UPDATE: Section 321 Warning (Release 2) Set to Deploy January 18 U.S. Customs and Border Protection sent this bulletin at 01/17/2025 03:33 PM EST Cargo Systems Messaging Service CSMS # 63791838 - UPDATE: Section 321 Warning (Release 2) Set to Deploy January 18 On January 18, 2025, U.S. Customs and Border Protection (CBP) will deploy the second release of the Section 321 – Does Not Exceed $ 800 in Aggregated Shipments enhancement to the Automated Commercial Environment (ACE). This enhancement, rescheduled from January 11, 2025, will provide a warning in ACE when a de minimis shipment may exceed the $ 800 per person/per day threshold. This release will include electronic data interchange (EDI) impacts. For more information about the Section 321 warning, review the trade information notice: Section 321 – Does not exceed $ 800 in Aggregated Shipments – Release 2 . A rescheduled post-deployment support will be conducted as follows: January 23, 2025, at 1:00 PM ET Join via Microsoft Teams Participants are encouraged to join at the start of the call when CBP will provide a brief deployment status update. A question-and-answer segment will follow. Calls may end early if all questions have been addressed. Additional calls may be scheduled if demand warrants. For support questions related to this deployment, please contact the Cargo Release, Manifest, and Export Product Division at crem@cbp.dhs.gov . For technical questions, please contact the ACE Account Service Desk (ASD) at 866-530-4172 or ace.support@cbp.dhs.gov . Related CSMS messages: # 63650246 , # 63705053 , # 63737318 , # 63746323 Update your subscriptions, modify your password or e-mail address, or stop subscriptions at any time on your Subscriber Preferences Page . You will need to use your e-mail address to log in. If you have questions or problems with the subscription service, please contact subscriberhelp.govdelivery.com . This service is provided to you at no charge by U.S. Customs and Border Protection . Privacy Policy | GovDelivery is providing this information on behalf of U.S. Department of Homeland Security, and may not use the information for any other purposes. Powered by Privacy Policy | Cookie Statement | Help

Frequently asked questions

What is CSMS 63791838?

CSMS 63791838 is a U.S. Customs and Border Protection (CBP) Cargo Systems Messaging Service bulletin titled "UPDATE: Section 321 Warning (Release 2) Set to Deploy January 18". CSMS bulletins are the operational instructions CBP issues to brokers, importers, and ACE filers covering rate changes, system updates, scope guidance, and other day-to-day customs-operations changes.

When was CSMS 63791838 published?

CBP published CSMS 63791838 on January 17, 2025. The bulletin's instructions are typically operative as of the publication date unless the body specifies a different effective date.

Is the CBP CSMS the legally binding instruction?

Yes — for at-the-border filing and entry collection. CSMS messages translate Commerce's Federal Register determinations into operational CBP instructions that ACE/ACS systems and brokers execute. The Federal Register notice is the underlying legal authority; the CSMS is the operational implementation. Both should be read together when reconciling a rate or scope change.

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