Import duty on compression-ignition internal combustion piston engines from the United Kingdom

Duty on a $10,000 entry of HTS 8408.90.90.10

An estimate for planning only: U.S. Customs and Border Protection (CBP) determines the final duty on your entry. Priced against tariff measures version 2026-10-06.

How much is the import duty on compression-ignition internal combustion piston engines from the United Kingdom?

A shipment of compression-ignition internal combustion piston engines classified under HTS 8408.90.90 and made in the United Kingdom currently pays a total of 10.00% in U.S. import duty. That total is built from two lines, not one: the Column 1 general rate of Free (this subheading is duty-free under the normal tariff), plus the Section 301 forced-labor action of 10.00% charged under Chapter 99. Customers who look up only the base rate in the tariff schedule and stop there are under-budgeting this shipment by 10.00%.

The duty stack, line by line

U.S. duty on this code is assembled from separate legal instruments, each with its own authority. Here is what each line on the entry is:

The base line is HTS 8408.90.90.10 itself at Free, the ordinary most-favored-nation rate that applies to every origin with normal trade relations with the United States.

HTS 9903.05.81 adds 10.00% under the Section 301 forced-labor action — in force since 24 July 2026 across 60 economies including United Kingdom, charged on the entered value on top of the Column 1 rate and following the origin of the goods rather than the route they travel.

Worked example: a $10,000 shipment

Take one ocean shipment of compression-ignition internal combustion piston engines with an entered value of $10,000 — the customs value of the goods, before freight and insurance. At 10.00%, the duty is $1,000.00. Of that, $0.00 is the Column 1 duty and $1,000.00 is Chapter 99 additional duty. On top of the duty, the entry attracts a merchandise processing fee of $34.64 and, because it arrives by vessel, a harbor maintenance fee of $12.50. Duty and fees together come to $1,047.14, and the engine puts the landed cost of the goods at $11,047.14.

These are ad valorem rates, so a $100,000 entry of the same goods carries about $10,000 in duty, though MPF is capped per entry. Run your own value, entry date and HTS code through the import duty calculator for the same calculation against the same engine.

What changed, and when

The rate on this code has moved. Priced with an entry date of 15 October 2025, the same shipment would have paid 0% — the Column 1 rate alone, with no Chapter 99 line. Today it pays 10.00%, higher by 10.00 percentage points.

One thing that is often confused with this: IEEPA tariffs are not part of the calculation. The Supreme Court ruled against the IEEPA program on 20 February 2026, and this engine applies no IEEPA duty on any entry date. Every line above is Section 301, 232, 201 or 122 — separate statutes, unaffected by that ruling.

Between those two points sits the Section 122 balance-of-payments surcharge. Priced at 15 May 2026, inside the surcharge window, the same $10,000 entry would have paid 10.00% ($1,000.00), with the surcharge appearing as HTS 9903.03.01 at 10.00%. Section 122 ran from 24 February to 23 July 2026 and then expired by operation of law, so it does not apply to entries filed now. If you are reconciling a spring-2026 entry summary against a quote from today, that expired line explains most of the gap.

MPF, HMF and what else lands on the entry

Duty is not the whole bill to Customs. The merchandise processing fee is ad valorem with a statutory floor and ceiling per entry — $34.64 on this $10,000 example. The harbor maintenance fee is charged on vessel arrivals only, $12.50 here; the same shipment flown in would pay no HMF.

Not in any of these figures: antidumping and countervailing duties, excise taxes, quota charges, bond costs, and the freight and brokerage that make up the rest of your landed cost. AD/CVD is worth checking before you commit to a supplier — it is assessed on the producer and exporter, not just on the HTS code, and it can dwarf the tariff.

U.S. imports of 8408.90.90 from the United Kingdom

Between March and July 2026 the U.S. imported $1.4 billion under HTS 8408.90.90 from the 55 origins in this dataset; $461 million of it — 33.1% — came from the United Kingdom, making United Kingdom one of the larger suppliers on this subheading. The largest were the United Kingdom (33.1%), Japan (18.3%), Mexico (8.9%), Germany (8.7%) and France (7.1%).

Census also reports duty actually collected: entries of HTS 8408.90.90.10 from the United Kingdom paid an average effective duty of 10.00% of value over those months. That tracks the 10.00% priced here closely, a good sign the stack above reflects what importers really pay. Treat it as a sanity check on your own numbers, not a forecast of your entry.

Our Heavy Machinery & Industrial Equipment guide covers packing, classification and handling for this cargo type in more depth than a duty page can.

Planning around this number

Classification drives this: the page prices HTS 8408.90.90.10, the largest 10-digit line under 8408.90.90 for United Kingdom by import value, and a neighboring line in the same subheading can carry different Chapter 99 exposure. Entry date matters as much as origin — the gap between the dates above is a change in law, not in your goods.

Airlift USA does not hold a U.S. customs broker license — customs entries are handled through our licensed broker network, and the broker of record makes the classification and origin calls. These figures are estimates for planning, produced by the same engine behind our import duty calculator; U.S. Customs and Border Protection determines the final duty on your entry.

How the duty on this shipment changed by entry date

What HTS 8408.90.90.10 covers

Compression-ignition internal combustion piston engines (diesel or semi-diesel engines) > Other engines > Other > Not exceeding 149.2 kW

Rates can differ from one 10-digit line to the next, so confirm your classification with a licensed customs broker before you rely on this figure. Other 10-digit lines under 8408.90.90: 8408.90.90.10, 8408.90.90.20, 8408.90.90.40, 8408.90.90.50.

Common questions about duty on HTS 8408.90.90 from the United Kingdom