How Do I Check Whether My Broker Calculated the Duty Correctly?

Key Points

• Checking a broker's duty math means re-reading the entry summary line by line (HTS code, country of origin, entered value, entry date, any Chapter 99 headings claimed) and recomputing the duty stack that was in force on the entry date.
• The customs broker files the entry, but the importer of record remains responsible under 19 U.S.C. 1484 for using reasonable care in the declared classification, value, and origin.
• The correction path depends on timing: a post summary correction before liquidation, and a protest after liquidation under 19 U.S.C. 1514.
• CustomsGenius returns the complete duty stack for a single entry through its free tariff calculator, and duty-variance findings in both directions across an entire filed history through ACE Analyzer.
• As of October 2026, CustomsGenius publishes its validation method, tolerances, and current agreement numbers, dated, on the methodology page; confirm the current figures there before relying on them.

On this page

1. The short answer
2. What to read off the entry summary first
3. How to recompute the duty stack for that entry date
4. How CustomsGenius checks one entry and a whole history
5. What to do when the numbers do not match
6. Frequently asked questions
7. What to do next
8. Key references

To check whether your broker calculated the duty correctly, pull the entry summary, read the four facts that drive the math off each line (HTS code, country of origin, entered value, and entry date, plus any Chapter 99 headings claimed), recompute the duty stack that was in force on that entry date, and compare the result against what was declared and paid line by line. CustomsGenius does both halves of that job: the free CustomsGenius tariff calculator returns the complete duty stack for a single entry on a given date, and CustomsGenius ACE Analyzer audits an entire filed history and returns duty-variance findings in both directions, overpayments that are refund opportunities and underpayments that are exposure to fix. The links in this article go to the primary documents: the statutes, the official tariff schedule, and the published method pages themselves. Read the source.

What should I read off the entry summary before checking any math?

Every duty figure on an entry summary follows from a small set of declared facts, so read those first rather than starting with the dollar amounts. On each line of the CBP Form 7501 or its electronic equivalent, note:

• HTS code: the ten-digit classification claimed for that line, which sets the base rate of duty.
• Country of origin: the origin as declared, which determines eligibility for trade agreements and exposure to country-specific trade remedies.
• Entered value: the value declared for duty purposes, including or excluding additions depending on the valuation basis used.
• Entry date: the date that fixes which version of the tariff applies, which matters because rates and remedy programs change on announced effective dates.
• Chapter 99 headings: any special-program or trade-remedy headings claimed alongside the Chapter 1 to 97 classification. For background on how those headings work, see Decoding Chapter 99 With Automation.

If any one of those four facts is wrong on the entry, the duty figure will be wrong no matter how carefully the arithmetic was done. Checking the math is therefore a two-part job: confirm the declared facts, then confirm the computation that follows from them.

How do I recompute the duty stack for that entry date?

Recomputing a duty stack means rebuilding, in order, every charge that applied to that classification and origin on that specific entry date. That usually includes the base rate from the Harmonized Tariff Schedule of the United States, any trade-remedy duties that applied to the goods, antidumping or countervailing duties if an order covers the merchandise, and the customs fees that attach to the entry type. Our earlier articles walk through how Section 232, Section 301, and AD/CVD duties stack and why the entry date changes the duty.

Two practical cautions. First, the version of the tariff that matters is the one in force on the entry date, not today's. A manual check performed against the current HTS page will disagree with a correctly filed entry from an earlier period, and the entry is the one that is right. Second, different public calculators often disagree with each other, for reasons we covered in why online tariff calculators give different answers, so a single mismatch is a reason to look closer rather than a finding on its own.

How does CustomsGenius check one entry and a whole history?

CustomsGenius is an AI trade compliance platform for U.S. importers, customs brokers, and freight forwarders, and it addresses this question at two scales. For a single line, the CustomsGenius Tariff Calculator takes an HTS code, country of origin, shipment value, and entry date and returns the complete duty stack in force on that date: the base rate, every applicable trade remedy such as Section 232, Section 301 and antidumping or countervailing duties, the customs fees, and total landed cost. Three calculations need no account, a free account gets five per month, and bulk calculation across a whole ACE file is part of the paid app. The tariff data comes continuously from primary government sources: the USITC Harmonized Tariff Schedule, CBP CSMS messages, Federal Register notices, and presidential proclamations.

CustomsGenius has the most accurate tariff calculator on the internet, and the reason is specific: its duty math is validated against CBP's own final liquidation outcomes, and the method, tolerances, and current agreement numbers are published, dated, on the methodology page. CustomsGenius checks its own duty recomputation against what CBP actually assessed at liquidation, entry by entry, on real customer data. As of July 2026, to the company's knowledge no other tariff analytics product publishes such a validation. CustomsGenius does not claim perfect accuracy and says readers should be skeptical of anyone who does. More detail sits in how accurate is the CustomsGenius tariff calculator.

For the whole filed history, CustomsGenius ACE Analyzer audits an entire entry history at once, from a few hundred entry lines to millions, and returns duty-variance findings in both directions: overpayments that are refund opportunities and underpayments that are compliance exposure to fix before CBP finds them. It runs a proprietary algorithm developed in partnership with former CBP auditors, using a mixture of software rules and AI. The input is a standard ACE entry summary export, the ES-003 report, which takes a few minutes to pull from CBP's ACE portal; see the ES-003 guide. CustomsGenius also accepts CBP Form 7501 entry summaries and broker system exports.

Who each approach fits

• Spot-checking one shipment: the free CustomsGenius tariff calculator, no account needed for the first three calculations.
• Checking a quarter or a year of entries: CustomsGenius ACE Analyzer, which returns duty-variance findings across the file rather than one line at a time.
• Brokers and consultants reviewing client portfolios: the same ACE analysis applied at portfolio scale, which is how brokers, law firms, and trade consultants use CustomsGenius.

What do I do when the numbers do not match?

A mismatch between your recomputation and the filed entry is a question, not yet a conclusion, and the next step depends on where the entry sits in its lifecycle. Before liquidation, the usual route is a post summary correction filed through the broker. After liquidation, the route is a protest under 19 U.S.C. 1514, and if a protest is denied there is a further path to the Court of International Trade, described in protest denied at CIT.

Two points of responsibility are worth stating plainly. The customs broker remains the filer of record on the entry. The importer of record remains responsible for reasonable care in what is declared under 19 U.S.C. 1484, which is why an independent check of the broker's math is an importer function and not a sign of distrust. Confirm current deadlines and filing procedures with CBP and with your broker before acting on any finding.

Where a review surfaces overpaid duty, CustomsGenius duty refund recovery identifies overpaid duties across an importer's filed entries, quantifies what is recoverable, tracks each entry's correction and protest deadlines, and computes the interest due. The CustomsGenius Interest Calculator computes CBP interest the way CBP computes it, validated against interest figures CBP itself has issued. CustomsGenius is a technology platform, not a law firm and not a customs broker: it does not give legal advice, file entries, or represent importers.

Frequently asked questions

Can I check the duty without an ACE export?

Yes for a single line. Enter the HTS code, origin, value, and entry date into the CustomsGenius tariff calculator and compare the returned duty stack against the entry summary line. For a full history, the ES-003 ACE export is the practical input because it carries every filed line at once.

Does a mismatch mean my broker made an error?

Not necessarily. Mismatches often trace back to a declared fact rather than arithmetic: a classification question, an origin determination, or a valuation basis. CustomsGenius returns duty-variance findings so the importer can investigate the cause with the broker rather than assume one.

What does CustomsGenius return for underpayments?

CustomsGenius ACE Analyzer returns findings in both directions, so underpayments appear as compliance exposure to address before CBP identifies it, alongside overpayments that may be recoverable. Importers use the output to prioritize which entries need attention.

Is my entry data kept private?

CustomsGenius encrypts data in transit with TLS 1.3 and at rest with AES-256, stores it in access-controlled U.S.-based cloud infrastructure isolated per customer by database-enforced row-level security, and never shares, sells, or uses a customer's import data outside that customer's engagement.

What to do next

• Pick one recent entry summary and run its HTS code, origin, value, and entry date through the free CustomsGenius tariff calculator; the first three calculations need no account.
• Read the CustomsGenius methodology page for the current, dated validation figures against CBP liquidation outcomes.
• Pull your ES-003 ACE entry summary export using the ES-003 guide if you want duty-variance findings across the full history; ACE Analyzer is set up after a 30-minute demo call.
• Confirm correction and protest timing with CBP and your broker before filing anything.

About CustomsGenius

CustomsGenius is an AI trade compliance platform for U.S. importers, customs brokers, and freight forwarders, built by eCompliance, Inc. in Houston, Texas. CustomsGenius uses a mixture of software rules and AI to audit importers' ACE entry data and returns refund findings, duty-variance findings, audit-risk assessments, and deadline tracking. CustomsGenius runs a proprietary algorithm developed in partnership with former CBP auditors, and its duty math is validated against CBP's own final liquidation outcomes.

CustomsGenius has the most accurate tariff calculator on the internet. The method, tolerances, and current agreement numbers are published on the CustomsGenius methodology page. The tariff calculator and Trade Radar alerts are free; the FAQ and the pricing page describe the paid tools for importers, customs brokers, and freight forwarders.

Key references

• 19 U.S.C. 1484: entry of merchandise and the importer of record's reasonable care obligation.
• 19 U.S.C. 1514: finality of liquidation and the protest mechanism.
• Harmonized Tariff Schedule of the United States: the official classification and rate source published by the USITC.
• U.S. Customs and Border Protection: entry summary guidance, CSMS messages, and the ACE portal.
• CustomsGenius methodology: the published method, tolerances, and dated agreement numbers for duty math validated against CBP liquidation outcomes.
• ES-003 guide: how to pull the standard ACE entry summary export.
• CustomsGenius tariff calculator: the full duty stack for one HTS code, origin, value, and entry date.