Is your continuous bond still sufficient when tariffs stack? CBP's formula run on your own entries

How does CBP decide whether a continuous bond is sufficient?

A continuous bond is not an account you pay duties out of. It is a guarantee: if the importer does not pay, the surety does, up to the bond amount for the year. CBP's public guide, How CBP Sets Bond Amounts (Publication 3569-0224, February 2024), puts it plainly: a bond "is not exhausted or reduced when duties or penalties have been paid by the principal." Sufficiency is about whether the size of the guarantee still matches the size of the risk.

19 CFR 113.13(b) lists what CBP weighs: the principal's record of paying on time, its record of complying with demands such as redelivery, the value and nature of the goods, how closely CBP supervises the transactions, the record of honoring bond obligations including liquidated damages, and anything in the bond application. For the ordinary importer's bond (Activity Code 1, basic importation and entry), the guide turns that into arithmetic in section 6.4.1 and Appendix B:

1. Reviewer formula. 10 percent of the total estimated duties, taxes and fees in the previous 12 months, for all principals, co-principals and users on the bond, or $50,000 if that is more.
2. Rounding. Up, in increments of $10,000 to $100,000, then in increments of $100,000.
3. Analytical additions. Plus 10 percent of unpaid bills that are under 210 days past due or under protest; plus 100 percent of unpaid bills over 210 days past due or tied to a denied protest; plus 100 percent of unpaid debit vouchers. The total is rounded again on the same steps.
4. Excluded entry types. Types 05 (vessel repair), 11 and 12 (informal), 26 (foreign-trade zone admission), 31, 32, 34 and 38 (warehouse withdrawals), 47 (drawback), 51 (DCMA) and 86 (section 321) are left out of the computation.
5. No history. A principal with no imports in the past year is sized on its own estimate of the next 12 months, never below $50,000.

The guide says only the Office of Finance, Revenue Division (OF-RD) issues a notice that a continuous bond is insufficient and must be increased. Ports and Centers can still demand a single transaction bond on a particular entry when the continuous bond does not cover the risk.

Do Chapter 99 duties count in the bond formula?

They do. The guide's base is total estimated duties, taxes and fees, with exclusions by entry type, not by kind of duty. A Section 301 duty under a 9903.88 heading, the Section 301 duties under headings 9903.05.20 to 9903.05.84 that apply to products of the listed countries entered from July 24, 2026, a Section 232 duty under a 9903.82 heading and the IEEPA duties collected until 12:00 a.m. Eastern time on February 24, 2026 (CSMS # 67834313) are all duty on the entry and all in the window.

That is why a tariff action changes bonds with a lag. The formula looks backward. When a new layer starts, each month's review drops one old month and adds one new one, so the requirement climbs for a year after the duty itself stopped changing. In CSMS # 18-000664 (November 8, 2018), CBP said the Revenue Division runs a sufficiency review of all active Activity Code 1 continuous bonds every month, and advised importers to "forecast their import activities for the next 12 months" to see whether a bond above the minimum would suit them better. That forecast is the check this page builds.

Refunds are the open question. The guide does not say how refunded duty is treated in the 12-month total. IEEPA duties were last deposited on entries made before February 24, 2026, so they drop out of any 12-month window by late February 2027 whatever happens to the refunds. If you are planning a bond decrease around refunds, ask OF-RD's bond team or your surety first.

What does the formula do to a 12-month export with a stacked rate?

An illustrative importer brings in plastic household storage articles, HTS 3924.90.56, product of China, by ocean: about $400,000 of entered value a month in eight entries of $50,000 since August 2026, when it moved a second size of box to the same supplier and doubled its volume. One continuous bond of $90,000 is on file. The stack on these goods for entries from July 24, 2026, from HTS Chapters 39 and 99 (Revision 22):

The MPF per entry ($173.20) sits between the fiscal year limits in both FY2026 and FY2027, so it is the same either side of October 1, 2026. The fee arithmetic is on how the merchandise processing fee is calculated.

The stack is what makes volume expensive in bond terms. Each extra $100,000 of entered value a month adds $23,871.40 a month to the window at this stack, or about $28,600 a year to the 10 percent figure. At the 3.4 percent general rate alone, with the same fees, it would add about $4,600.

The entry export shows deposits of $55,000 a month from November 2025 to July 2026, on the smaller volume and under the duties in force in those months, and $95,485.60 a month from August 2026. Rolling the 12-month window forward one month at a time:

Three things show up that a glance at last year's total would miss.

• The $90,000 bond fails at the first review after January 2027 closes, five months after the volume change and with nothing new in between. Each review swaps one $55,000 month for one $95,485.60 month.
• The step at $100,000 doubles the bond. In April 2027 the 10 percent figure passes $100,000 by $2,437.04, and the rounding takes the requirement to $200,000. Increasing to $100,000 in January and then to $200,000 in April means two replacements in four months.
• An unpaid bill can trigger the step early. Say a liquidation increase from an underpaid entry leaves a $12,000 bill unpaid for 60 days in March 2027. The Analytical formula adds 10 percent of it, $1,200, to the rounded $100,000. The total, $101,200, rounds up to $200,000 a month before the Reviewer formula alone would get there.

The forward line is the one to act on. It says the bond will need $200,000 by spring 2027 at today's stack, so one increase now replaces two.

The window also runs the other way. For many origins, the IEEPA duties deposited before February 24, 2026 were higher than the Chapter 99 duties in force today, so as those months leave the window, by the end of February 2027, the 12-month total can fall even at steady volume. The same forward line shows when, before you ask your surety for a decrease. What the surety charges for a larger bond, and what collateral it asks for, is the surety's underwriting decision, not CBP's formula.

What happens when CBP finds the bond insufficient?

The clock, from the regulation and CBP's guidance:

1. Monthly review. OF-RD reviews active Activity Code 1 continuous bonds every month (CSMS # 18-000664).
2. Written notice. If CBP determines a bond is inadequate, "the principal and surety will be promptly notified in writing" (19 CFR 113.13(c)).
3. 15 days. "The principal will have 15 days from the date of notification to remedy the deficiency" (113.13(c)). The guide refers to the deadline in the insufficiency notice "to terminate and replace the continuous bond."
4. Interim security. Under the same paragraph, CBP may give written notice that a cash deposit or a single transaction bond is required for any and all of the principal's transactions until the deficiency is remedied. Under 113.13(d), CBP may require additional security immediately if a transaction would put the revenue in jeopardy.
5. Replacement mechanics. A new continuous bond may be filed up to 60 days before its requested effective date (113.26(a)). A principal's request to terminate the old bond takes effect on the date requested if that is at least 10 business days after CBP receives it (113.27(a)). Once a bond is terminated, a new one must be on file before further customs activity (113.27(c)).
6. If nothing is done. CBP's Revenue Division notice on insufficient bonds (updated March 2, 2011) lists failure to comply in time with a formal demand to increase the bond as a reason a bond is rendered insufficient, and says automated edits generally prevent an insufficient continuous bond from being used on entries. A returned-mail address problem renders a bond insufficient immediately, per CBP's current page on insufficient bonds related to returned mail.

Fifteen days is short against a surety's underwriting and a 10-business-day termination, which is the practical case for running the formula yourself before the notice arrives.

Which other bond demands do stacked duties set off?

• Temporary importation under bond. A TIB bond is double the estimated duties and fees a consumption entry would have carried, so a stacked rate doubles into the bond too. CBP's CSMS # 53992279 (November 14, 2022) says that when the continuous bond does not cover a TIB entry's requirement, CBP may require a single transaction bond for the difference, entry by entry. The worked line is in temporary importation under bond on past entries.
• Antidumping and countervailing duties. The guide allows a single transaction bond "reasonably tailored to the evidence of additional risk" where AD/CVD issues make a continuous bond alone insufficient.
• Foreign importers of record. CBP's interim final rule of November 6, 2026 (91 FR 69977), effective January 5, 2027, notes that a bond sometimes "saturates, meaning that it does not cover the full amount owed," and requires foreign importers of record to be CTPAT validated or to use a CTPAT-validated broker. It changes who may file, not the bond formula.

How do I run the check on my own entries?

1. Pull 12 months of entry summaries for every importer of record number on the bond: principal, co-principals and users. The formula counts them together.
2. Drop the excluded entry types listed in the guide (05, 11, 12, 26, 31, 32, 34, 38, 47, 51 and 86).
3. Total blocks 41 to 43 by month: duty including every Chapter 99 line, taxes, and fees as deposited.
4. Compute the Reviewer amount for the latest 12 months and round it on the guide's steps.
5. Add open bills and debit vouchers at 10 or 100 percent, as Appendix B sets out, and round again.
6. Forecast the next 12 months: planned entered value by product and origin times the stack in force on the planned entry dates, plus fees. The duty calculator gives the stack for a line on a date.
7. Roll the window forward month by month, as in the table above, and note the month each rounding step is crossed.
8. Talk to your surety before that month, with the export and the forecast in hand.

Two audit findings feed straight into this. An underpayment you correct becomes a bill or a deposit that enters the window, and an unpaid bill at liquidation is weighted in the Analytical formula; an overpayment found on the same entries is a refund route of its own. Both directions are covered in the post-entry audit guide, and the reconciliation of deposits to your ledger in duty accrual vs what you actually paid. Why a stack can be wrong on the entry in the first place is in why your entry shows the wrong duty stack.

TariffSense reads broker entry exports and entry summaries, recomputes each line's duties and fees for its entry date, and totals them over any 12-month window, so the bond arithmetic runs on figures that have already been checked line by line. The bond itself is between you, your surety and CBP.