What Is Tariff Audit Software? A 2026 Guide

Why "tariff audit" became a live category in 2026

A customs entry is priced once, on the day your broker files it, against whichever version of the duty rules is live that morning. Nothing re-prices it afterward. In most years that barely matters, because the rules barely move. In 2026 the Supreme Court struck down the IEEPA tariffs on February 20 and CBP began refunding them through the CAPE system inside ACE; the replacement Section 122 surcharge arrived February 24 and now survives on appeal only until July 24 absent action by Congress; and Section 232 on steel, aluminum, and copper was restructured on April 6, moving duty onto the full customs value of a much longer list of derivatives.

Each change carries its own effective date, so a year of entries has a correct price that depends on the filing date, line by line. This guide separates the five offerings that now answer to the phrase; it is part of The Manufacturer's Guide to Checking Your Tariff Bill, which covers the full recheck end to end.

The five things "tariff audit" can mean

The phrase covers five approaches with different pricing, coverage, and blind spots. None is wrong; they fit different companies.

1. Contingency recovery firms

Accounting and law firm practices that take your entry data, run their own review, and charge a percentage of whatever they recover, usually unpublished. No upfront fee, no internal effort; the trade is opacity. Ask any firm in this lane two questions: which rule versions do you price against, and do I get the line-level workpapers either way?

2. A customs broker's manual review

For a bounded question, like whether an exclusion was claimed on five specific lines, your broker is the right and cheapest answer. A manual review cannot scale: it is sample-based in practice, and re-pricing thousands of lines against rules that changed mid-year is compute work, not judgment work. The broker also files the corrections for every other approach: the last mile of all of them.

3. Tariff audit engines

The software version of the category. An engine ingests your entry data and rebuilds every line's duty against effective-dated rules: the rate as of March 3 for a March 3 entry, not the rate as of today. Coverage is the full population of lines, not a sample. Three questions for this lane: does it price per entry date, does it reconcile totals against what you actually paid, and does it show the per-line arithmetic so your broker can file from the output?

4. Duty drawback software: a different category

A neighboring category answering a different question: drawback refunds up to 99 percent of eligible duties on imported goods later exported, used to make exported goods, or destroyed under CBP supervision, reaching back five years from import. Drawback recovers duty on goods that left the country; a tariff audit corrects what you paid on the goods that stayed. If you do not export, drawback is not your category, whatever the pitch says.

5. Procurement intelligence

The newest angle: connecting each entry line to the PO, the supplier invoice, and the contract behind it, because the most expensive error classes are invisible in customs data alone. This is Kynthar's lane; it gets the last section of this guide.

Which fits when: choose by profile, not feature list

Entry volume, export activity, and in-house expertise decide this almost by themselves:

• A few dozen entries a year or fewer. Ask your broker for the 7501s and check the highest-duty entries by hand. Software is optional at this volume; the method is identical either way.
• Hundreds to thousands of entry lines. Engine or contingency firm. Contingency costs nothing up front and takes a cut plus your visibility into the method; an engine shows the work, but you still file through your broker. For an in-house trade team, an engine is leverage: reviewing line-level findings instead of maintaining rate spreadsheets by hand.
• You export. Add drawback regardless of what else you run: five years is the longest window of any pathway, and it stacks with an audit of the goods that stayed.

And if your tariff costs arrive on supplier invoices rather than your own entries, none of the customs-side approaches can see the problem. That case is the last section of this guide.

What data you need to start

Every approach starts from the same records, and you already own them: the entry summaries (CBP Form 7501) your broker filed, an ACE export of your own entries if you are the importer of record, and the supplier invoices behind them. What each document is and where to get it is covered in the line-by-line guide. If you can pull an ACE report, you can start an audit this week; every approach above asks for the same files.

What a finding actually looks like

A finding is not a refund. It is a documented claim you file through your broker or counsel, carrying five things: the entry and line reference, what was charged, what the rules in force on that entry date required, the dollar difference, and the recovery pathway with its computed deadline.

A line entered March 3, 2026: machine parts from China, entered value $28,000, Section 301 List 4A duty at 7.5 percent, $2,100 paid. The invoice description matches one of the 178 Section 301 exclusions active through November 10, 2026, but no exclusion was claimed. Rules as of March 3: exclusion available, duty owed on that program zero. The finding: $2,100 on one line, recoverable by Post Summary Correction, with the cutoff computed from the scheduled liquidation date. That last clause is the part software should do on every finding: the pathway and deadline change with each entry's dates.

The refund deadline reality

Whichever approach you choose, recovery runs through the same doors, and the windows are statutory:

• Post Summary Correction: reaches back 300 days from the entry date, and no later than 15 days before scheduled liquidation.
• Protest (CBP Form 19): 180 days from the liquidation date, absolute, no extensions.
• CAPE: refunds of the struck-down IEEPA duties only, live in ACE since April 20, 2026.
• Drawback: five years from import, on exported or destroyed goods.

Entries liquidate continuously, on schedules CBP sets, so a year of entries has hundreds of deadlines scattered across the calendar. That is not a vendor countdown; it is how the statute works. The routing logic per finding is in the refund pathways guide; verify every window with your broker.

What the estimates claim, and what is checkable

The industry estimate quoted everywhere puts duty overpayments at 5 to 15 percent of duties paid. Treat it as marketing from firms selling recovery services; it may be right, but you cannot check it. What we can verify first-party: in a recent run, Kynthar's duty engine priced $2.32 million of duty across 532 entry lines and reconciled the total to the dollar. The claim worth buying from anyone in this category is not a percentage; it is that the math is checkable, line by line, against your own documents.

Where customs-only auditing stops

Everything above, engines included, runs on customs-side data: the 7501 lines and ACE records of the importer of record. That data answers one question well: did we pay CBP the right amount, given what was declared? It cannot tell you whether the declaration was right, and it cannot see tariff charges that never touched CBP. Three error families live in that blind spot:

Value errors. The entry declares a customs value; the PO and supplier invoice say what you actually agreed to pay. When they diverge, every ad valorem duty on the line is computed on the wrong base.

Origin errors. Origin decides which programs apply at all. A supplier that moved production, or an origin copied from an old item setup, shows up in the commercial paper trail, not on the 7501.

Supplier surcharge double-recovery.If you are the importer of record, you paid the duty to CBP once. A supplier "tariff surcharge" on the same imported goods has no duty basis on that leg; it is legitimate only to the extent the supplier can tie it to tariff costs it actually paid upstream. That reconciliation can only run in your POs and supplier invoices joined to the duty rules, and no customs-side tool ever sees those documents. Even companies that import nothing have this bill: their suppliers are the importers, and the surcharges are their tariff cost.

That reasoning is the procurement-intelligence version of the category, and the one Kynthar was built around: the audit is stronger when every entry line connects to the PO, the invoice, and the contract behind it, because the value, the origin, and the surcharge all live there. It is also why the tariff check asks for the supplier invoices alongside the 7501s.