FDA Prior Notice must be filed before your shipment arrives at a US port of entry, with the required lead time depending on how the goods are being transported.
The FDA sets minimum advance filing windows based on how the shipment is being transported, since different transportation methods have different processing realities and arrive on different timelines.
Minimum filing windows by transportation method
- International mail — the Prior Notice must be filed before the goods are sent, since mail shipments don't have a predictable, trackable arrival window the same way commercial freight does
- Land, by road — at least 2 hours before the shipment's arrival at the port of entry
- Land, by rail — at least 4 hours before arrival
- Air — at least 4 hours before arrival
- Water, by ocean freight — at least 8 hours before arrival
These are legal minimums set by the FDA, not recommended targets. Filing right at the minimum window leaves no buffer if there's an error that needs correcting, which is why most experienced filers, including specialist services, aim to file well ahead of these deadlines rather than right up against them.
Why filing earlier is almost always the better choice
There's no meaningful downside to filing a Prior Notice further in advance than required, as long as the shipment details are accurate and finalized. The benefits of an earlier filing are mostly about risk reduction:
- If the FDA's system flags something for clarification, there's time to respond before the shipment is already in transit or at the border
- If you discover an error in your own filing, there's room to correct it without missing the legal window entirely
- It removes the operational pressure of needing to file at the exact moment a shipment departs, which is often when a business is busiest and most likely to make a mistake
What if your shipment details change after filing?
If something changes after you've already submitted a Prior Notice, such as a shipment being delayed, a change in carrier, or a change in quantity, the filing generally needs to be updated to reflect the actual shipment. Submitting a Prior Notice for one set of circumstances and then shipping something materially different can create a mismatch that triggers a hold, even if the original filing was technically submitted on time.
What happens if you file too late, or not at all?
If a Prior Notice isn't filed within the required window, US Customs and Border Protection has the authority to refuse admission of the shipment. In practice, this typically means the goods are held at the port of entry until a valid Prior Notice is filed and processed, which can range from a short delay to a much longer hold depending on the circumstances, the product type, and how quickly the issue is resolved.
For perishable goods specifically, like many food products, delays caused by a missing or late Prior Notice can be more costly than for non-perishable goods, since spoilage or quality degradation becomes a real risk the longer a shipment sits at the border.
Building Prior Notice timing into your shipping workflow
For businesses shipping to the US regularly, the safest approach is to treat Prior Notice filing as a standard step that happens automatically alongside every shipment, rather than something handled manually and separately each time. Many businesses build this in by either filing well in advance as a standard practice, or by using a service that handles the timing requirements automatically as part of label creation or order processing, removing the need to track transportation-specific deadlines manually for every single shipment.