A useful tariff estimate has a trail of evidence: which product was reviewed, which import rules were used, and which assumptions still need an answer. Before using an estimate in a purchase order or customer quote, assemble that trail for each SKU.
This checklist focuses on imports into the United States. It is a document-gathering and review workflow; it does not establish a current duty rate for any product.
1. Give the product a complete description
Create a short product file containing its model number, function, materials and composition, dimensions, technical specifications, and condition when imported. Include photographs or existing drawings, a supplier specification sheet, and the bill of materials where relevant. Record whether it arrives as a finished item, an incomplete item, parts, or a retail set.
Ask the supplier what facts support its proposed code. A commercial name such as “accessory” rarely gives a reviewer enough information.
The international HS identifies goods at six digits; final classification follows the importing jurisdiction's tariff schedule. A supplier's longer export code therefore needs a destination-specific check. See the WCO's Harmonized System FAQ.
2. Verify the complete U.S. classification
Use the product file to review the relevant heading, subheadings, interpretation rules, and legal notes. For U.S. entry reporting, confirm the complete ten-digit HTS number. A keyword match alone is insufficient, and the eight-digit legal subheading is where the ordinary tariff rate is assigned. The USITC classification FAQ explains these distinctions.
Keep a brief classification memo with:
- The selected code and the product facts supporting it.
- Any plausible alternative code and why it was rejected.
- The tariff edition, relevant notes, and links used.
- Any question that still needs technical information or a specialist's review.
3. Separate manufacturing origin from the shipping route
Request the manufacturing locations and a description of the work performed at each location. Add component origins, production records, and any evidence supporting a preferential-origin claim. Keep the seller's address and shipping route in separate fields.
Origin rules depend on the purpose of the determination. In its discussion of U.S. marking rules, CBP describes a fact-specific substantial-transformation assessment; it does not treat every assembly operation as origin-conferring. See CBP ruling H320225. Do not apply that test automatically to every preference program or product-specific rule.
For review, frame the question precisely: which origin rule applies to this product and claimed treatment, and which manufacturing facts satisfy it?
4. Reconcile the value and the units
Collect the purchase order, commercial invoice, payment terms, freight and insurance breakdown, quantities, and currency. Identify separately any buyer-supplied tooling or materials, selling commissions, royalties, or other payments that may need valuation review.
CBP's commercial-invoice valuation guidance explains that the price paid for the goods, relevant additions, and the applicable duty basis matter. Some duties use quantity or volume rather than a percentage of value. Have the reviewer confirm the treatment of each cost item instead of assuming the invoice total is always the duty base.
5. Check each possible duty layer and its timing
Use a separate worksheet row for the ordinary tariff, any applicable Chapter 99 measure, a claimed exclusion or preference, and any trade-remedy issue. For each row, record the official authority, applicability decision, calculation basis, and relevant effective date. Keep unresolved rows visibly marked as pending.
Chapter 99 can change the treatment of goods classified elsewhere in the HTS. Antidumping and countervailing duties require a separate check because they are not listed in the HTS. The USITC FAQ on additional duties and AD/CVD identifies the relevant official resources.
Record the shipment dates needed by the actual measure. Do not assume that an order date, sailing date, or arrival date answers every effective-date question. Likewise, avoid simply adding every percentage found in a search: first confirm whether each measure applies and how the applicable instructions interact.
6. Hand over an auditable estimate
Give the importer or customs broker one review packet with these fields:
- SKU and version of the product specification.
- Proposed U.S. HTS number and classification reasoning.
- Origin determination, applicable rule, and supporting production documents.
- Customs value worksheet, currency, and reported units.
- Duty layers reviewed, source links, and effective-date assumptions.
- Open questions, responsible reviewer, and date checked.
If a material classification or origin question remains, consider a ruling request before the planned import. CBP's binding-ruling request guidance describes the eligible subjects and the transaction facts to provide. A complete product file makes that next step easier.
Keep the resulting estimate alongside its evidence and revisit it when the product, manufacturing process, supplier, or applicable rules change. You can use DutyTrade's route explorer to organize initial research, then verify the shipment's treatment with the official sources and supporting documents above.