Post-Entry Customs Audit: What It Checks and What It Finds

A post-entry customs audit reviews the entries your broker already filed and checks each line for errors that cost you money or create compliance risk: HTS classification, customs value, country of origin, trade preference claims and Chapter 99 duties such as Section 301, 232 and IEEPA. Overpayments go to a Post-Summary Correction or a protest. Underpayments go to a correction or a prior disclosure. Most importers have never had one, because their broker's job ends when the goods clear.

What a customs audit checks

• HTS classification: Whether each product is classified under the right 10-digit number, which sets the duty rate and which Chapter 99 duties apply.
• Customs value: Whether the declared value includes what it should, such as assists and royalties, and excludes what it may, such as certain freight and insurance.
• Country of origin: Whether origin is right, which decides Section 301 and other country-specific duties.
• Trade preferences: Whether USMCA or other preference claims were made where the goods qualified.
• Chapter 99 stacking: Whether Section 301, Section 232 and IEEPA lines were applied where they belong, and only there.
• Fees: Whether the Merchandise Processing Fee respects its per-entry minimum and maximum, and whether the Harbor Maintenance Fee was charged correctly.

What happens to each finding

• Overpaid and unliquidated: A Post-Summary Correction, within 300 days of entry and at least 15 days before liquidation.
• Overpaid and liquidated: A protest within 180 days of liquidation.
• IEEPA duty: A CAPE declaration.
• Underpaid: A correction, or a prior disclosure under 19 U.S.C. 1592(c)(4), which reduces penalty exposure when filed before CBP opens an investigation.
• Repeating errors: A fix in the product catalog and broker instructions so future entries are filed right.

How often should importers audit?

The windows set the cadence. A PSC closes 15 days before liquidation and a protest 180 days after it, so an annual audit misses most of the correctable entries. A continuous audit checks entries as they are filed, while every route is still open.

Who needs a customs audit?

• Importers with high duty rates or heavy Section 301, 232 or IEEPA exposure.
• Importers with large catalogs, where classification drifts as products change.
• Companies that changed brokers or sourcing countries in the last two years.

Frequently asked questions

Is a customs audit the same as a CBP audit? No. A CBP audit, such as a Focused Assessment, is run by the government. A post-entry audit is one you run on your own entries, ideally before CBP does.

Will an audit find underpayments too? It can. Finding them yourself and correcting them is far better than CBP finding them.

What data does an audit need? Your ACE entry summary data, your product catalog and, for valuation, your purchase records.

How Caspian audits entries

Caspian's post-entry audit reads every entry summary line in your ACE history against the tariff schedule and your product data, flags the errors, and routes each one to the correction that is still open. Licensed brokers on our team file the PSCs and protests. See our trade audit or the guide to recovering overpaid duties.

Works Cited:

• 19 U.S.C. 1514, Protest against decisions of CBP
• 19 U.S.C. 1592, Penalties and prior disclosure
• CBP: Post-Summary Corrections