How we show our math: inside the DrawbackAI methodology

A drawback estimate is only useful if a trade-compliance team can trace it. The headline number matters, but the audit trail matters more: which import line created the recovery, which export or destruction event supports it, which calculation limited it, which duty types were excluded, and which part of 19 U.S.C. § 1313 and 19 CFR Part 190 applies.

That is the core of the DrawbackAI methodology. We do not treat drawback as a black-box percentage of imports. We build the estimate from the transaction line up, preserve the math, and label the result with the evidence level behind it.

The goal is simple: if CBP, a broker, a controller, or an internal auditor asks “where did this dollar come from?”, the answer should be visible without rebuilding the whole analysis.

The unit of analysis is the line, not the shipment

Drawback is filed and supported with line-level data. Under 19 CFR § 190.51(a)(2), a complete drawback entry includes, among other things, the drawback provision claimed, the refund amount by duty, tax, and fee type, and for each designated import entry line item: the entry number, line number, description, ITIN, HTSUS classification, duties paid, entered value, quantity, unit of measure, and other duties, taxes, or fees claimed.

So our estimate starts there. We ingest import entry data, normalize it to the entry-line level, and keep the line identifiers intact. We do the same for exports, destructions, bills of materials, inventory records, transfer records, and, where relevant, manufacturing rulings.

A shipment-level estimate can look clean and still fail when someone asks which line was designated. A line-level estimate may take more work, but it is the level at which the claim has to survive.

Step 1: identify the potential pool

First, we identify import lines that may carry recoverable duties, taxes, or fees. The legal starting point is broad: drawback may be allowable on duties, taxes, and fees imposed under federal law upon entry or importation, including ordinary customs duties, certain internal revenue taxes, merchandise processing fees, and harbor maintenance taxes. The regulation also states what is not allowable, including antidumping and countervailing duties. See 19 CFR § 190.3.

DrawbackAI separates those categories before any recovery estimate is presented. A line can have both recoverable and nonrecoverable amounts. We do not collapse them into one duty total.

For each import line, we tag the duty basis: ordinary duty, Chapter 99 duty, MPF, HMF, internal revenue tax, AD/CVD, and any tariff-action-specific duty. Then we apply the eligibility rule that controls that duty type. If a governing statute, regulation, proclamation, or executive order bars drawback for a duty type, that dollar is excluded and shown as excluded.

Step 2: map the legal pathway

Drawback is not one rule. It is a set of pathways under 19 U.S.C. § 1313, implemented through 19 CFR Part 190.

DrawbackAI classifies each potential match by claim theory before calculating the refund. The main pathways we evaluate include direct identification manufacturing drawback, substitution manufacturing drawback, direct identification unused merchandise drawback, substitution unused merchandise drawback, rejected merchandise drawback, and certain special provisions such as petroleum derivatives or packaging when applicable.

That classification matters because the evidence, time limits, substitution standard, and calculation can change. A substitution unused merchandise match under 19 U.S.C. § 1313(j)(2) is not the same analysis as a manufacturing claim under 19 U.S.C. § 1313(a) or § 1313(b).

Step 3: test the time window

A strong product match is not enough if the timing fails. For unused merchandise drawback, 19 U.S.C. § 1313(j) generally requires exportation or destruction before the close of the five-year period beginning on the date of importation and before the drawback claim is filed. 19 CFR § 190.51(e) also addresses completion, abandonment, and special timeframes for claims.

DrawbackAI therefore runs timing tests before assigning estimated recovery. We compare import date, export date, destruction date, claim-filing window, and any special pathway rule. If the match is outside the window, we do not erase it. We show it as excluded for timing.

That distinction matters in practice. A CFO may see a high duty line and expect recovery. The compliance answer may be: “the dollar exists, but the export occurred too late.” Showing that excluded value prevents a false negative in the data and prevents a false positive in the estimate.

Step 4: match imports to exports or destruction events

The matching engine looks for evidence that an import line can be designated against an export, destruction, returned merchandise event, or manufactured article. The relevant evidence depends on the claim type.

• For direct identification, we look for a traceable relationship between the imported merchandise and the exported or destroyed merchandise: part number, serial number, lot, SKU, inventory movement, warehouse record, commercial invoice, export document, or other normal-course record.
• For substitution unused merchandise, we test the classification and statutory criteria, including the same eight-digit HTSUS standard where applicable under 19 U.S.C. § 1313(j)(2).
• For manufacturing drawback, we connect imported or substituted inputs to finished articles using bills of materials, formulas, production records, manufacturing rulings, and quantities.
• For rejected merchandise, we test whether the fact pattern fits the rejected-merchandise basis: nonconforming, defective at importation, shipped without consent, or qualifying retail return, and whether the documentation supports it.

For exports, 19 CFR § 190.72 requires proof establishing the date and fact of exportation and the identity of the exporter, with summary data such as date of export, exporter, description, quantity, unit of measure, Schedule B or HTSUS number, and country of ultimate destination. We treat that as a data requirement, not an afterthought.

When the evidence is strong, the match can move into the estimate. When it is incomplete, the line is flagged for review. When it fails a legal or data test, it is excluded with a reason code.

Step 5: apply the lesser-of rule and the 99% factor

The visible estimate is built after the legal pathway, timing, duty-type, and matching tests are applied. For many drawback claims, the calculation starts with the 99% factor. For substitution claims, the calculation may also be limited by the “lesser-of” rule.

In plain English, substitution drawback cannot simply use the higher of the import duty paid or the duty that would apply to the exported or destroyed merchandise. The statute and regulations generally cap the refund at 99% of the lesser amount. That is why DrawbackAI calculates both sides where the rule applies.

This is where many rough estimates overstate recovery. If the import line paid a higher duty rate than the exported substitute would have paid on importation, the lesser-of rule can reduce the claim. If the exported article would have paid more, the import duty paid can become the cap. Either way, the estimate should show the limiting side.

DrawbackAI labels that limit. A user should be able to see whether a dollar was limited by import duties paid, export-side hypothetical duties, the 99% factor, an excluded duty type, recovered material value, or an evidence gap.

Step 6: allocate fees and duty types separately

Duties, taxes, and fees do not always behave the same way. 19 CFR § 190.3 identifies categories that may be subject to drawback, including merchandise processing fees and harbor maintenance taxes, and categories that are not. 19 CFR § 190.51(a)(2)(vii) requires the amount of refund claimed for each relevant duty, tax, and fee.

That is why our methodology does not produce only one blended percentage. We keep a duty-type ledger for each line. The estimate can show recoverable ordinary duty, recoverable MPF, recoverable HMF, excluded AD/CVD, excluded IEEPA where applicable, and other line-level adjustments.

This also helps prevent double counting. If a duty dollar is unavailable for drawback, already claimed, barred by a tariff action, or tied to another refund process, it should not silently remain inside the drawback estimate.

Step 7: assign confidence to every match

A calculation can be mathematically correct and still rest on weak evidence. DrawbackAI therefore assigns confidence at the match level, not just at the account level.

The confidence label is not a legal conclusion. It is an evidence signal. It tells the user how much support exists for the match and what needs review before filing.

• High confidence: line identifiers, quantities, dates, classifications, and export or destruction records align; no exclusion is detected; the statutory pathway is clear; and the required records appear complete.
• Medium confidence: the match is plausible, but one or more fields need trade-compliance review, such as unit-of-measure conversion, product identifier mapping, indirect transfer records, or export documentation quality.
• Low confidence: the match depends on incomplete, conflicting, or inferred data. We may show the possible value, but we do not present it as filing-ready.
• Excluded: the dollar is not counted in estimated recovery because a legal, timing, duty-type, prior-claim, or evidence rule blocks it.

The confidence score is paired with a reason. “Medium” without explanation does not help a broker or compliance manager. “Medium—Schedule B maps to multiple HTSUS candidates; classification review required” is useful.

Step 8: show a low–high range, not false precision

Drawback estimates live between data and law. Some lines are clean. Some need classification review. Some depend on whether the client can produce transfer records, manufacturing records, or proof of exportation. Some duty actions require current review because tariff programs change.

For that reason, DrawbackAI shows a low–high range. The low end includes the more conservative, better-supported recovery. The high end includes additional potential recovery that may be available if flagged assumptions are validated.

The range is not a way to soften the answer. It is a way to make the answer more honest. A single number can imply certainty the data does not support. A range, with reasons, lets the team decide where review effort is worth spending.

A drawback estimate should be a map, not a magic number.

Step 9: preserve the audit trail behind the number

For each dollar in an estimate, we preserve the path back to its source data. A typical audit trail includes the import entry number, import line number, duty type, duty paid, eligible duty basis, export or destruction reference, match rule, statutory pathway, calculation, limitation, confidence level, and exclusion reason if applicable.

For manufacturing claims, the audit trail also needs to connect the input to the finished article. 19 U.S.C. § 1313(b)(3) addresses bills of materials or formulas for substitution manufacturing claims, including records that identify the component and article by eight-digit HTS subheading and quantity. 19 CFR § 190.51(a)(2)(ix) requires manufacturing-claim information such as ruling numbers, factory location, basis of claim, dates of use, descriptions, classifications, quantities, disposition, and MTINs.

That is why our output is structured for review. A broker should be able to filter by claim type, duty type, exclusion code, confidence level, and missing documentation. A compliance team should be able to hand the workbook or export to an internal reviewer and explain the result line by line.

Why excluded duties are part of the answer

Many drawback projects underperform because excluded dollars disappear from the discussion. The analysis says, “estimated recovery is $X,” but it does not say that another $Y was excluded because it was AD/CVD, outside the window, governed by a no-drawback tariff action, or unsupported by export records.

That creates two problems. First, finance may not understand why recovery is lower than expected. Second, compliance may lose a useful checklist of issues to validate. Some exclusions are final. Others may be curable with better records, corrected product mapping, or broker review.

DrawbackAI treats exclusions as a separate schedule. We show the amount, line, duty type, reason, and authority where available. The excluded schedule is part of the methodology because it explains both what the estimate includes and what it deliberately leaves out.

Why this matters at liquidation

A drawback estimate is not the same thing as a liquidated refund. CBP reviews drawback claims and may request additional evidence. Under 19 CFR § 190.52, CBP may reject incomplete or untimely claims, may request additional evidence, and may deny a claim if it later determines the claim was incomplete or untimely. Under 19 CFR § 190.81, drawback entries are liquidated under the regulatory process.

That is why the methodology is designed around review, not presentation. The estimate should help the claimant prepare for the questions CBP may ask: What import line was designated? What export proves the claim? What rule supports substitution? What duty types were claimed? What was excluded? What records support the calculation?

If the only support for an estimate is “the software said so,” the estimate is not ready for a serious drawback program. If the support is a line-level record, statutory pathway, calculation, and document trail, the team can review it, challenge it, improve it, and decide whether to file.

How we handle uncertainty

Uncertainty is not failure. It is information. DrawbackAI separates uncertainty into categories so the user can act on it.

• Data uncertainty: missing quantities, inconsistent product identifiers, unit-of-measure conversions, incomplete duty breakdowns, or entry-line data that needs broker validation.
• Legal uncertainty: a claim theory that requires counsel, broker, or ruling review; a tariff-action-specific drawback restriction; or a special rule for a product category.
• Classification uncertainty: export classifications, Schedule B to HTSUS mapping, or substitution standards that need classification review.
• Documentation uncertainty: missing proof of exportation, transfer records, manufacturing records, destruction records, or certifications.

Each category affects the confidence level and the low–high range. A clean line with complete documents should not be discounted because another product family has weak records. Likewise, a high-value but unsupported match should not inflate the base estimate.

What a good estimate lets you do

An auditable estimate gives the trade team options. It can prioritize the biggest recoveries, isolate document gaps, decide whether a manufacturing ruling or privilege application is worth pursuing, identify excluded duty categories, and coordinate with the broker before filing.

It also helps finance understand the difference between potential, supportable, and claim-ready recovery. That distinction is important because drawback is cash, but it is compliance cash. The refund depends on the claim, the records, and CBP’s liquidation.

DrawbackAI’s job is not to make the number look bigger. It is to make the number explainable.

The standard we use

Our standard is that every estimated dollar should be explainable in one sentence and supportable in the underlying record: this import line, matched to this export or destruction event, under this subsection, calculated this way, limited by this rule, with this confidence level.

That standard is stricter than a rough opportunity scan. It is also more useful. It gives importers, exporters, brokers, and compliance teams a shared view of what can be claimed, what needs review, and what should stay out of the claim.

In drawback, the best estimate is not the highest estimate. It is the number you can audit.

This article is for general information and is not legal or tax advice. Drawback eligibility depends on your specific facts, and final refunds are determined by CBP at liquidation. Consult a licensed customs broker or attorney for your situation.