Exactly how matching works

Principles

• Proposals, not decisions. The software proposes. You accept or decline every match.
• Reasons and warnings travel with every proposal. If a match is questionable, you see why, and it is held out of the default total until you decide.
• Traceable figures. Every amount comes from lines you uploaded and the arithmetic below. No statistical or learned model is used to match records or to compute amounts.
• Order of upload does not matter. Proposals are re-planned across all your records each time you run matching, so splitting a file in two gives the same result as uploading it once.

What the software reads

Import lines: entry number, entry date, optional date of importation, line number, 10-digit HTS number, SKU, quantity, unit of measure, optional entered value, and duty, tax and fee amounts by type. Export lines: export reference, date, line number, HTS or Schedule B number, SKU, quantity, unit, destination country, optional export value and port, and prior notice status and reference. Entry numbers and export references are compared ignoring case and punctuation, so "ab1-2345678-9" and "AB123456789" are one entry. Exports to the United States or Puerto Rico are rejected on upload because they are not exports. Import lines with no eligible duty, and lines already past their deadline, are left out of matching.

Which duties count

The eligible duty for a line is the sum of the duty types the software treats as eligible. The rules are stored as reference data and shown on your upload page.

Section 201 duty has no column of its own yet. Tariff programs change, so confirm treatment with your broker.

The 99 percent cap

Drawback refunds up to 99 percent of the eligible duties, taxes and fees (19 U.S.C. 1313(l)). All estimates apply that cap. It is a ceiling set by the statute, not a typical result.

Direct identification

A match is proposed as direct identification when all of these are true:

• The import and export lines carry the same real SKU. Empty cells, dashes, zeros and placeholders such as N/A, TBD or "unknown" identify nothing and never match.
• The HTS numbers agree on the first 8 digits. If the SKUs agree but the first 8 digits differ, the pair is not matched (it is not treated as the same article). If only the 10-digit numbers differ, the match carries a warning asking you to confirm it is the same article.
• The units agree after normalizing common synonyms (for example EA, EACH and PCS, or PR and PRS). Different units such as dozens and each, or pounds and kilograms, do not match. The software does not convert units.
• The export is on or after the date of importation and within 5 years of it.

Refund estimate: 99 percent of the line's eligible duty, scaled by the matched quantity over the line quantity.

Order. The software plans direct identification first, for all of your exports in date order, and only then proposes substitution from the quantity that is left. An import line used for one basis is not offered to the other.

Allocation. Where several import lines share a SKU, the software proposes that each export draws on the oldest eligible line first (by entry date, then entry number, then line number; substitution uses the same order). That is a proposal, not an inventory accounting method approved by CBP (19 CFR 190.14), because the software does not see your domestic sales or other receipts. Before a worksheet is created you state the method you actually keep records under, and your broker confirms it.

Substitution

A match is proposed as substitution when all of these are true:

• The HTS numbers agree on the first 8 digits, unless that 8-digit subheading is a residual provision whose description begins with "Other". In that case the 10-digit statistical numbers must match, and the 10-digit description must not itself begin with "Other" (19 U.S.C. 1313(j)(5)).
• Units agree and the export is inside the same date window as above.
• The export destination is not Canada, Mexico or Chile, and not the U.S. Virgin Islands, Guam, American Samoa or the U.S. Minor Outlying Islands. Substitution is not available for those destinations.

The "Other" test uses the United States International Trade Commission's published HTS data, loaded into the software. It must be refreshed when the HTS is revised. A subheading the data does not know is treated as not residual, so confirm unusual numbers with your broker.

The lesser-of limit

For substitution, the refund is limited to 99 percent of the lesser of the duty paid on the imported goods and the duty the exported goods would bear if they were imported (19 U.S.C. 1313(l)(2)(B)). The software estimates the export-side figure by scaling the import duty by the ratio of export unit value to entered unit value, never above 1. That is a simplification: your broker works out the true export-side duty from the export HTS rate and value. Without both values, no refund is computed and the match is held out.

One basis per import line

A single entry summary line cannot be split between direct identification and substitution (19 CFR 190.51(a)(3)). Once a line is used for one basis, the software will not propose the other for the rest of that line, and it refuses to put a split line on a worksheet.

The 5-year window

The filing deadline for a line is 5 years from the date of importation, which is not always the entry date. The software applies no extension: the statute allows one only if CBP caused the late filing or after a declared major disaster (19 U.S.C. 1313(r); 19 CFR 190.51(e)). The software uses the import date you supply. If you supply none, it uses the entry date and warns you to verify. Lines past their deadline are excluded from matching and from every total, and are shown as expired. An export must also fall on or after the import date and within the 5 years.

Duplicate shipments

If two export references have the same date, destination, HTS number, SKU, quantity and unit, the later one is flagged as a possible duplicate and its matches are held until you mark it as a separate shipment. Which of two duplicates is flagged depends on upload order.

Warnings that hold a match out

A match with a blocking warning cannot be accepted and is left out of the default total. A match that needs an acknowledgement can be accepted only after you confirm it.

Arithmetic

Money is handled in whole cents with exact integer arithmetic. Each match keeps its exact fractional amount, and totals are rounded down once at the end, not line by line.

What the software does not check

It does not verify your data against ACE, check proof of export, confirm who the claimant is, track liquidation status, apply the tariff rate to the export value, or decide which accounting method you may use. The not supported yet page lists the rest.

Sources and currency

Legal basis: 19 U.S.C. 1313 and 19 CFR Part 190. These rules describe the software as of 2026-10-19. The law, CBP guidance and tariff programs change, and this page is not a substitute for your broker's reading of them.