AMS filing: the 24-hour rule, and what “AMS” now means
The 24-hour clock is measured from lading at the foreign port, not from sailing and not from your carrier’s documentation cut-off. What the trade still calls AMS, and what an NVOCC takes on the day it decides to self-file.
The Automated Manifest System is the name the trade still uses for the advance electronic cargo declaration a carrier transmits to US Customs and Border Protection before cargo moves to the United States. For ocean freight it is due 24 hours before the cargo is laden aboard the vessel at the foreign port — the 24-hour rule. Since 29 September 2012, CBP has treated ACE as the only approved electronic data interchange through which rail and sea manifests may be transmitted.
AMS, ACE and ISF are three different things
Two of them are commonly confused because they share a clock. The cargo declaration is the carrier’s obligation under 19 CFR 4.7: the CBP-approved electronic equivalent of the vessel’s Cargo Declaration, CBP Form 1302, due 24 hours before lading. The Importer Security Filing is the importer’s obligation under 19 CFR part 149, due on the same 24-hour clock but transmitted separately, by a different party, against a different bond. Filing one does not discharge the other.
ACE is not a third obligation — it is where the manifest now goes. “AMS” survives as trade shorthand for the manifest transmission itself, and you will still see it on booking confirmations, in charge codes and in software menus, which is why it is worth being precise about which of the two you mean when an origin office says the AMS “has been sent”.
The deadline, by mode
| Mode | Advance cargo data due | Rule |
|---|---|---|
| Ocean, containerised | 24 hours before lading at the foreign port | 19 CFR 4.7(b)(2) |
| Ocean, bulk and qualifying break bulk | 24 hours before the vessel’s arrival in the United States | 19 CFR 4.7(b)(4) |
| Air, from most origins | 4 hours before arrival in the United States | 19 CFR 122.48a(b)(2) |
| Air, from nearby areas — North America, Central America, the Caribbean, Bermuda and South America north of the equator | No later than departure — wheels up, en route directly to the United States | 19 CFR 122.48a(b)(1) |
| Air, ACAS screening data | As early as practicable, and before the cargo is loaded onto the aircraft | 19 CFR 122.48b |
| Rail | 2 hours before the cargo reaches the first US port of arrival | 19 CFR 123.91 |
| Truck | 30 minutes or 1 hour before arrival, depending on the CBP-approved system used | 19 CFR 123.92 |
| Vessel stow plan (carrier) | 48 hours after departure from the last foreign port; before arrival on voyages under 48 hours | 19 CFR 4.7c |
| Container status messages (carrier) | 24 hours after the message enters the carrier’s equipment tracking system | 19 CFR 4.7d |
Note what the ocean deadline is measured from. It is lading at the foreign port, not sailing and not the carrier’s documentation cut-off. On a service that calls several load ports, the box can be aboard days before the vessel leaves the last one.
Who transmits, and what an NVOCC needs
The obligation sits on the incoming carrier. A non-vessel operating common carrier may transmit its own house bill data instead of passing it to the vessel operator, and the transmission is identified by SCAC — the unique Standard Carrier Alpha Code assigned to each carrier. At master bill level on a consolidated shipment, 19 CFR 4.7a treats the identity of the NVOCC, freight forwarder or container station as sufficient; the underlying houses are declared beneath it.
That election carries the liability with it. An NVOCC that elects to transmit electronically and then fails to do so as required, or transmits a document that is forged, altered or false, may be liable for liquidated damages under its international carrier bond, at $5,000 for each violation discovered (19 CFR 4.7a; 19 CFR 113.64(c)). The separate statutory penalty at 19 U.S.C. 1436(b) — $5,000 for a first violation and $10,000 for each subsequent one — reaches the master, the person in charge of a vehicle or the aircraft pilot rather than the NVOCC; the NVOCC’s own exposure is the liquidated damages figure above, claimed against its bond, which is a different instrument with a surety, a bond capacity and a petition process behind it. Self-filing is not free of consequence just because it removes a co-loader’s charge.
What goes wrong
- The master is filed and the houses are not. The vessel operator declares the master bill, the NVOCC assumes it is covered, and the house bills never reach CBP. The container is manifested; the cargo on it is not.
- Two parties file the same house. The co-loader transmits and the NVOCC transmits, and CBP receives duplicate house bills against one master. This is the most common cause of an unexplained hold at destination.
- SCAC and bill number do not match between filings. CBP associates the ISF, the manifest and the entry through the bill of lading. A house number that differs by a prefix between systems is, from CBP’s side, a shipment with no matching filing.
- Amending after the 24 hours has run. Once the cut-off passes, an amendment is a correction to a filing that was already due, not a fresh filing on a fresh clock.
- The AMS is treated as covering the ISF. Different party, different regulation, different bond. See the Importer Security Filing and who is liable for it.
- Land-border work is run on ocean habits. Truck and rail arrivals into the US from Canada or Mexico run on 30-minute, 1-hour and 2-hour clocks, not a 24-hour one; the differences are set out in AMS entry requirements for Canada to US shipments.
How software handles it
The manifest is not new data — it is the house and master bills you have already raised, expressed in the format CBP expects, against the right SCAC, before a clock that starts at lading. What a system contributes is a single record where the master, its houses, the parties and the container all live together, so the manifest is generated from the file rather than re-keyed into a portal and reconciled by hand afterwards. Linbis prepares and validates AMS and ISF data on the shipment and hands it off for transmission, with master and house bills and manifests produced from the same record — the consolidation mechanics behind that are in ocean shipment handling for forwarders and NVOCCs.
Questions operators ask
What does AMS stand for?
Automated Manifest System — CBP’s electronic cargo manifest transmission. In current practice the required advance ocean and rail cargo information is filed in ACE, which CBP describes as the only approved electronic data interchange for those manifests since 29 September 2012, but the trade still calls the transmission “AMS”.
Is AMS the same as ISF?
No. AMS is the carrier’s cargo declaration under 19 CFR 4.7. ISF is the importer’s security filing under 19 CFR part 149. They share a 24-hour deadline and nothing else — different party, different data, different bond.
What is the 24-hour rule?
The requirement that CBP receive the electronic equivalent of the vessel’s Cargo Declaration 24 hours before the cargo is laden aboard the vessel at the foreign port (19 CFR 4.7(b)(2)). Bulk cargo, and break bulk to the extent provided in the regulation, is instead due 24 hours before arrival.
Can a freight forwarder file AMS?
An NVOCC may elect to transmit its own house bill data, identified by its SCAC, rather than hand it to the vessel operator — and takes on the corresponding liquidated damages exposure under its international carrier bond when it does.
Is there an AMS filing for air freight?
Air has its own advance data regime rather than the ocean 24-hour rule: the inward manifest under 19 CFR 122.48a, which is due four hours before arrival or at wheels-up depending on where the flight originates, plus ACAS data before loading under 122.48b.
Our carrier files the AMS for us — why would we want this in a system?
Because the exposure that follows a bad filing is usually not the carrier’s. Duplicate houses, mismatched bill numbers and unfiled houses are data problems that originate in your file, and they surface as holds and demurrage on your customer’s container. Keeping the master, the houses and the parties on one record is what makes the transmission correct on the first attempt. Linbis starts at $150 per month including one user, with a free trial and no credit card.