Customs duty is a tax a government charges on goods imported into its territory, paid by the importer at the border before the goods are released. It's calculated using three things together, never one alone: the product's tariff classification (its HS code), its country of origin, and its customs value — the same product can carry a different duty rate purely by changing any one of those three inputs.
There's no such thing as "the" duty rate for a product category in the abstract — only the rate for that specific product, from that specific origin, at that specific value, on that specific day. Our guide on how to calculate import duty and landed cost walks through the full calculation.
What actually determines the duty rate?
| Input |
What it decides |
| Tariff classification (HS code) |
Determines which duty schedule the product falls under — the single biggest lever, since a small description change can shift the code entirely |
| Country of origin |
The same HS code can carry different rates depending on where the product legally originates, including preferential rates under trade agreements |
| Customs value |
The base the duty percentage is applied to — and how that base is built (goods only, or goods plus freight and insurance) differs by destination country |
| Trade remedies |
Anti-dumping duties, safeguard tariffs, and similar measures can stack an extra rate on top of the standard one, tied to specific product/origin combinations |
How is the duty amount actually calculated?
Most customs duty is ad valorem — a percentage of customs value — though some products carry a specific duty (a flat amount per unit or weight) instead. Where the ad valorem base starts from differs by destination: the EU calculates duty on the CIF value (goods plus freight and insurance), while the US calculates it on the goods' value alone, excluding freight. Two identical shipments to different markets can therefore owe different duty even at the same nominal rate, simply because the base is built differently.
Customs duty vs. import VAT vs. tariff
| Term |
What it is |
| Customs duty |
A tax on the import itself, based on classification, origin, and value — generally non-recoverable once paid |
| Import VAT |
A separate consumption tax charged at import, on top of duty — and, unlike duty, usually reclaimable with the right VAT registration |
| Tariff |
Often used interchangeably with "duty," though it can also refer more broadly to the schedule of rates itself, or to a politically imposed duty on a specific country |
The distinction between duty and VAT matters practically: duty paid is generally gone for good, while import VAT paid can usually come back to a properly registered business — which is why the two need to be modeled differently in a pricing calculation, not lumped into one number.
What do brands get wrong with customs duty?
- Assuming one duty rate per product forever. Rates change with trade policy, and can shift with little notice — a rate that was accurate last quarter isn't guaranteed to still be accurate, especially amid the kind of shifts covered in our piece on the recent US trade shakeup.
- Under-declaring value to reduce duty. Customs value must reflect the real transaction value — understating it is fraud, not a savings strategy, and it's checked against market data.
- Classifying loosely instead of precisely. A vague HS code guess can land a product in a higher-duty category than a precise, correctly documented one would — the paperwork itself can cost real money.
- Forgetting duty when pricing across markets. The same product can carry meaningfully different duty in different destinations once origin, classification base, and any trade remedies are accounted for — a single global price ignores real cost differences per market.
FAQ
What determines the customs duty rate on a product?
Three things together: the product's tariff classification (HS code), its country of origin, and its customs value. Changing any one of these — a different origin, a different classification, a different declared value — can change the duty owed.
Is customs duty the same as VAT?
No. Customs duty is a tax on the import itself and is generally non-recoverable once paid. Import VAT is a separate tax charged at the same time, but a properly VAT-registered business can usually reclaim it — the two need to be treated differently in cost calculations.
Can customs duty rates change without notice?
Yes. Duty rates are set by trade policy, which can shift due to new agreements, trade disputes, or executive action — sometimes with limited lead time. Landed cost models built on last year's rates can become inaccurate quickly during periods of active trade policy change.
Getting classification, origin, and duty calculation right on every shipment is core to accurate landed cost — and it's exactly what eBrands manages as your Merchant of Record. See how it works for physical-goods brands.
