Start with the general rule: duty is assessed under the law in force when the goods are entered for consumption, with warehouse and foreign trade zone mechanics able to shift that moment in specific ways. Tariff actions then layer their own effective date language on top: an increase may apply to goods entered on or after a date, with an in transit exception for goods loaded or exported before an earlier date and entered before a cutoff. The exception is never implied. It exists only if the action text grants it, in the terms the text uses.
That is why summaries mislead. On the water means one thing in one action, exported before a date, and something narrower in another, and the Federal Register or proclamation text for the specific action is the only version that decides a real shipment. The brokers job, and the importers discipline, is to read the actual language for the action in question rather than importing the last actions transition rule by habit.
Export date is set by the supply chain, entry date is partly a choice. Goods sitting in a bonded warehouse or a foreign trade zone have, within their rules, a timing decision attached: enter before a known increase and the earlier rate is captured, delay past a decrease and the lower rate may be. Privileged foreign status elections in a zone lock classification and rate at admission in a way that helps against increases and hurts against decreases, which makes the election a forecast that should be made deliberately, with the pending actions list open on the desk.
What cannot be controlled is an action announced and effective inside the transit window with no transition relief, which happens, and is the scenario cash flow planning should carry: a reserve for the plausible increase on goods afloat, priced into the order decision when an action is publicly pending. An importer surprised by a telegraphed increase has a planning gap, not bad luck.
Where a transition rule turns on export or loading date, the bill of lading and carrier records are the evidence, and they must match the entry claim exactly. A shipment consolidated, reloaded, or transshipped can carry several candidate dates, and the action text specifies which one counts, the date laden aboard the vessel that carries it to the destination in the classic formulation. Collect the transport documents for at risk shipments before arrival, while the carrier can still correct errors cheaply, not after entry when the file is being argued.
Keep the action text itself in the entry file: the proclamation or Register citation, the effective date clause, and the transition clause relied on. Audits of rate timing happen years later, staff have changed, and a file that contains the rule as written at the time answers in one page what memory cannot answer at all.
A rate change on goods afloat is a margin event for orders already priced and sold. The earlier the business hears the range, this programme of shipments, this exposure if entered after the date, the more options survive: entry timing, customer conversations for unshipped orders, price action for the next buy. The worst version is the duty bill arriving as a surprise inside a closed month, attached to products whose selling prices are history.
Build the pending actions watch into the landed cost review: open actions with future dates, shipments afloat matched against them, entry plans stated per shipment. It is an hour a week in a volatile tariff period, and it converts the most theatrical cost surprise in importing into a managed, dated, documented decision.
Keep reading: How do you spot landed cost drift when a supplier quietly changes pack sizes?, Which exception reports catch landed cost errors before month end close?.
Generally the rate in force at entry for consumption, modified by any in transit transition rule the specific tariff action grants. Those rules are action specific and often keyed to export date plus an entry deadline. The action official text decides, so it must be read for each measure.
Where goods have arrived and are eligible for entry, entering before the effective date captures the earlier rate. Bonded warehouse and foreign trade zone timing can also affect the entry moment, within their rules. The election has downsides if rates fall, so it should be a deliberate decision.
Transport documents, principally the bill of lading and carrier records showing the date the action text specifies, usually lading or export. The documents must match the claim exactly, and they are far easier to correct before arrival than after entry.
For goods afloat while an increase is publicly pending, yes. Model the exposure per shipment and carry it in the order economics. An announced increase landing on in transit goods is a foreseeable cost, and planning for it is cheaper than explaining it.