CSMS 5100409 is a U.S. Customs and Border Protection (CBP) Cargo Systems Messaging Service bulletin (trade policy), published on April 10, 2025. It carries the official CBP guidance brokers and importers must follow for the topic — "Notice of affirmative preliminary determination: antidumping duty investigation of Certain Corrosion-Resistant Steel Products from Mexico (A-201-863)". It links to 1 AD/CVD case in Tandom's catalog. 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.
Cases referenced or affected by this CSMS message
Full text as published by U.S. Customs and Border Protection
CSMS 5100409 is a U.S. Customs and Border Protection (CBP) Cargo Systems Messaging Service bulletin titled "Notice of affirmative preliminary determination: antidumping duty investigation of Certain Corrosion-Resistant Steel Products from Mexico (A-201-863)". 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.
CBP published CSMS 5100409 on April 10, 2025. The bulletin's instructions are typically operative as of the publication date unless the body specifies a different effective date.
CSMS 5100409 references 1 AD/CVD case (A-201-863). The links on this page take you to each linked order with its current scope, rates, and history.
Tandom guides relevant to CBP CSMS messages
Where trade compliance APIs fit in a broker's filing pipeline: HTS classification, duty calculation, AD/CVD scope match, and post-summary corrections.
Open resource
Cash deposit cascade, separate rates, all-others, and PRC-wide rates. Worked example on case A-570-910 (galvanized welded steel pipe from China) with three exporter-specific rates.
Open resource
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.
Scope text is authoritative; the HTS list is illustrative. Read scope, find past rulings, and file a 19 CFR 351.225 inquiry. Worked example on case A-570-106 (wooden cabinets from China).
Open resource