To calculate import duty, take the customs value of the goods and apply the rate for their tariff code: multiply by a percentage for an ad valorem duty, by the quantity for a specific duty, or both for a compound duty. The step people get wrong is the customs value. The US generally excludes international freight and insurance, while the UK and EU add transport costs up to their border, so the same shipment can produce a different duty bill. Import VAT, where it applies, is then charged on a base that includes the duty.
Key Takeaways
- Duty = customs value × rate, using that country’s valuation rules.
- The US excludes international freight; the UK and EU include freight to the border.
- UK import VAT is charged on a base that includes duty.
- Rules are as of October 2026; confirm before you ship.
The Basic Formula
Every customs authority follows the same three steps:
- Classify the goods to find the tariff code and its rate.
- Value the goods using that country’s valuation rules.
- Apply the rate, then add any taxes and fees charged at the border.
Duty rates come in three forms. An ad valorem rate is a percentage of value, such as 2.7%. A specific rate is a fixed amount per unit, kilogram or litre. A compound rate combines both. Most electrical products, including EV chargers and cables, carry ad valorem rates in the US tariff schedule at hts.usitc.gov, so value drives the result.
FOB vs CIF: Why the Value Base Changes the Answer
In the US, customs value is normally the transaction value, the price paid for the goods. CBP’s Customs Value publication explains that international freight, insurance and similar charges are excluded, while certain items such as packing, assists or royalties may need to be added. In practice the US base sits close to the FOB price.
The UK works differently. HMRC’s guidance on delivery costs in the customs value says transport, insurance, loading and handling up to the place the goods enter the UK must be included. The EU applies a similar border-inclusive approach. That base sits close to CIF.
Import VAT then builds on top. HMRC’s VAT value guidance says you add incidental costs to the first UK destination and any customs duty to the customs value before applying VAT.
Side-by-Side Example (Hypothetical Numbers)
Assume a shipment with a goods price of $20,000, international freight and insurance of $1,500, and a duty rate of 3%. The 3% rate and the 20% VAT rate are illustrative only, not the rate for any real product, and the example ignores extra trade-remedy layers.
| Step | US-style value (excludes freight) | UK-style value (includes freight to border) |
|---|---|---|
| Customs value | $20,000.00 | $21,500.00 |
| Duty at 3% | $600.00 | $645.00 |
| VAT base (value + duty, before UK incidental costs) | Not applicable | $22,145.00 |
| Import VAT at 20% (illustrative) | Not applicable | $4,429.00 |
The freight difference changes the duty by only $45 here. VAT is far larger, which is why UK and EU importers focus on recovering it through their VAT returns where they are eligible. US importers pay no import VAT, but must add processing and, for ocean freight, harbor maintenance fees.
Common Mistakes and How to Avoid Them
- Using the wrong code. One digit can change the rate. Confirm it with a broker.
- Forgetting additions. Paid-for moulds, tooling or royalties can belong in the value.
- Mixing bases. Do not apply a US-style FOB value to a UK or EU entry, or the reverse.
- Ignoring extra layers. Goods from China can carry additional US duties on top of the general rate.
If your question is specifically about stacking US duties on Chinese chargers, see our US import overview. Incoterms decide who pays freight in the first place, explained in FOB vs DDP, and our Canada guide covers another market’s rules.
EVDANCE issues clear commercial invoices that separate goods, freight and tooling, which makes valuation easier for your broker. Ask us for a quote on models such as the EV-ACT3204PE 22 kW wallbox. Valuation rules here are as of October 2026; confirm with the official guidance or a licensed customs broker.
Frequently Asked Questions
Is US duty calculated on FOB or CIF?
Generally on transaction value excluding international freight and insurance, which is close to FOB. Some additions may apply.
Is VAT charged on top of duty?
In the UK, yes: the VAT value includes the customs value, incidental costs and any duty.
What is a compound duty?
A rate that combines a fixed amount per unit with a percentage of value.
Related Reading
- FOB vs DDP: How to Import EV Chargers From China Without Surprises
- Importing EV Chargers Into the US: Customs, HTS and Section 301
- Canada EV Charger Import Guide: cUL, CSA and Duties
- How Much Does It Cost to Start an EV Charger Brand?
