CBP CSMS

Definition

CBP CSMS is the email-based operational-guidance channel used by US Customs and Border Protection to communicate with the trade community. CSMS messages cover topics including AD/CVD operational instructions, Section 301 implementation guidance, HTSUS update notices, tariff-rate-quota status, and system-outage announcements. CSMS messages are the closest thing to real-time CBP policy guidance — they often precede formal Federal Register publication by 24–72 hours. Importers and brokers should subscribe directly at cbp.gov; the CSMS archive is also searchable on the CBP site. CSMS messages are operationally binding on CBP officers at entry.