The AMS 24-Hour Rule requires ocean carriers and NVOCCs to submit complete cargo manifest data to AMS 24 hours before the cargo is laden onto a vessel at the foreign port of departure bound for the United States.
The rule was authorized by the Trade Act of 2002 in response to post-9/11 cargo security concerns and took effect December 2, 2002. It is codified at 19 CFR 4.7. The 24-Hour Rule is independent of, but complementary to, ISF 10+2 — both must be in place before vessel lading.
Required data includes:
- Vessel name and voyage number
- Bill of lading numbers (master and house)
- Shipper and consignee names and addresses
- Cargo description (precise — "FAK" or "freight all kinds" is not acceptable)
- Number and types of packages
- Container numbers and seals
- Weight and measurements
CBP uses the 24-hour window to perform Automated Targeting System (ATS) analysis and issue "Do Not Load" (DNL) instructions to carriers if a shipment is flagged for security reasons. Once a DNL is issued, the carrier cannot load the container — and the shipment must be cleared with CBP before any future lading attempt.
Penalties for late or inaccurate filing are issued against the carrier or NVOCC under their International Carrier Bond (ICB). The 24-Hour Rule and ISF together form the U.S. inbound advance-data backbone — both are filed before the cargo leaves the foreign port, not after arrival.