A continuous bond is not set and forget. CBP reviews bond amounts against actual import activity, and when duties, taxes, and fees on your entries outgrow the bond, a sufficiency notice follows. The bond has to be increased, usually within a short window, or entries start getting held. Most importers meet this rule for the first time in the middle of a busy shipping season.
How the minimum bond amount is set
For a continuous activity 1 bond, the minimum is generally 10 percent of the duties, taxes, and fees the importer paid in the previous 12 months, rounded up, with a floor of 50,000 dollars. An importer who paid 640,000 dollars in duties last year needs at least a 70,000 dollar bond after rounding, not the 50,000 dollar bond they started with.
That formula is why tariff increases trigger bond notices even when shipment counts stay flat. The same containers at a higher duty rate produce a bigger liability, and the bond has to track the liability, not the volume. Growth does it too. Any importer whose duty spend rose sharply should expect the letter.
Why the notice arrives when it does
CBP and sureties both monitor. A surety watching its aggregate exposure may flag the account first, or CBP issues the insufficiency notice after a periodic review. Either way the instruction is the same: file a larger bond, on a CBP Form 301 through a surety, within the period stated in the notice, commonly 15 days for a CBP demand.
Missing the deadline has mechanical consequences. A bond CBP deems insufficient can be rendered inactive, and without an active continuous bond, entries cannot be filed against it. Cargo does not stop arriving because the bond lapsed, which is how a paperwork deadline becomes a warehouse problem.
Sizing the replacement bond honestly
Sizing to last year's number repeats the cycle if imports are still growing. The practical approach projects the next 12 months: confirmed purchase orders, known rate changes including Chapter 99 actions already announced, and any new product lines entering at higher duty rates. Importers with spiky, seasonal volume should size for the peak rolling period, not the average month.
Single transaction bonds are the fallback for occasional importers, but for anyone filing regularly they cost more per entry and slow release. The continuous bond exists to be boring infrastructure. Keep it ahead of the duty curve and it stays that way.
What else rides on the same bond
The same continuous bond can secure several activities depending on how it was written, and insufficiency in one area can affect the rest. It is also the bond CBP looks at when an importer wants privileges like periodic monthly statement or participation in trusted trader programmes, where a clean, sufficient bond is table stakes.
Confirm the current minimum calculation and any activity specific requirements with a licensed customs broker or your surety before filing the replacement, because bond conditions and eBond filing mechanics change, and the notice period runs from the letter, not from when someone opens it.
Keep reading
Related guides on this site: Customs Recordkeeping: The Five Year File an Importer Must Be Able to Produce Reasonable Care for Importers: What It Means in Practice, Entry by Entry Answers for teams shipping Shopify orders across borders.
Frequently asked questions
How is a continuous customs bond amount calculated?
Generally at least 10 percent of the total duties, taxes, and fees paid in the previous 12 months, rounded up to the nearest 10,000 dollars, with a 50,000 dollar minimum for most continuous import bonds. Specific activities can carry higher minimums.
What happens if my bond is deemed insufficient?
CBP issues a notice requiring a larger bond within a stated period. If the bond is not increased, it can be made inactive, which means entries can no longer be filed against it until a sufficient bond is in place.
Can a tariff increase make my existing bond too small?
Yes. The minimum tracks duty liability, not shipment count. A rate increase on the same volume raises the 12 month duty total, and the bond minimum rises with it, which is why sufficiency notices clustered after major tariff actions.
Who provides the bond?
Bonds are written by surety companies approved by the Treasury and filed electronically in eBond, usually arranged through a customs broker. The importer is the principal and remains liable; the surety guarantees payment to CBP.