United Kingdom supplies 18.7% of U.S. imports of Certified Reference Materials, across 48 countries (year to date through August 2026).
HHI 939 of 10,000 · HHI below 1,000. The sum of each country’s squared percentage share; one country with everything scores 10,000.
48 countries supplying this product to the U.S.
| Rank# | Country | Value | Share | YoY | Duty |
|---|---|---|---|---|---|
| 1 | United Kingdom | $2.0M | 19.9% | -5.2% | 10.0% |
| 2 | Canada | $1.4M | 13.9% | -3.0% | 0.6% |
| 3 | Australia | $736K | 7.2% | +48.5% | 12.5% |
| 4 | Mexico | $709K | 7.0% | +232.9% | 0.0% |
| 5 | Austria | $652K | 6.4% | -1.4% | 10.0% |
| 6 | Vietnam | $553K | 5.4% | -2.9% | 12.5% |
| 7 | Germany | $544K | 5.3% | -7.5% | 10.0% |
| 8 | China | $489K | 4.8% | +4.5% | 12.5% |
| 9 | India | $429K | 4.2% | -11.8% | 10.0% |
| 10 | Japan | $419K | 4.1% | +9.4% | 12.5% |
| 11 | Italy | $314K | 3.1% | -94.6% | 2.3% |
| 12 | Turkey | $296K | 2.9% | -29.8% | 12.0% |
| 13 | Hungary | $245K | 2.4% | +24.6% | 10.0% |
| 14 | Belgium | $222K | 2.2% | +15.7% | 10.0% |
| 15 | France | $198K | 1.9% | -10.4% | 9.9% |
| 16 | Dominican Republic | $187K | 1.8% | -- | 12.5% |
| 17 | Netherlands | $149K | 1.5% | +16.4% | 10.0% |
| 18 | Denmark | $146K | 1.4% | -44.1% | 10.0% |
| 19 | Switzerland | $95K | 0.9% | -9.3% | 12.5% |
| 20 | Romania | $82K | 0.8% | -9.1% | 10.0% |
| 21 | Czech Republic | $42K | 0.4% | +74.4% | 10.0% |
| 22 | Spain | $41K | 0.4% | +47.4% | 10.0% |
| 23 | Sweden | $32K | 0.3% | -51.8% | 10.0% |
| 24 | Ireland | $31K | 0.3% | -74.6% | 10.0% |
| 25 | Taiwan | $23K | 0.2% | -90.9% | 9.1% |
| 26 | New Zealand | hidden | hidden | hidden | hidden |
| 27 | Poland | hidden | hidden | hidden | hidden |
| 28 | Singapore | hidden | hidden | hidden | hidden |
| 29 | Bulgaria | hidden | hidden | hidden | hidden |
| 30 | Hong Kong | hidden | hidden | hidden | hidden |
| 31 | Estonia | hidden | hidden | hidden | hidden |
| 32 | Ukraine | hidden | hidden | hidden | hidden |
| 33 | Portugal | hidden | hidden | hidden | hidden |
| 34 | Finland | hidden | hidden | hidden | hidden |
| 35 | Mongolia | hidden | hidden | hidden | hidden |
| 36 | Russia | hidden | hidden | hidden | hidden |
| 37 | Montenegro | hidden | hidden | hidden | hidden |
| 38 | Norway | hidden | hidden | hidden | hidden |
| 39 | South Korea | hidden | hidden | hidden | hidden |
| 40 | Latvia | hidden | hidden | hidden | hidden |
| 41 | Argentina | hidden | hidden | hidden | hidden |
| 42 | Greece | hidden | hidden | hidden | hidden |
| 43 | Brazil | hidden | hidden | hidden | hidden |
| 44 | Bosnia and Herzegovina | hidden | hidden | hidden | hidden |
| 45 | Israel | hidden | hidden | hidden | hidden |
| 46 | Qatar | hidden | hidden | hidden | hidden |
| 47 | Malta | hidden | hidden | hidden | hidden |
| 48 | Lithuania | hidden | hidden | hidden | hidden |
Duty is the duty Census calculated on this month's imports for consumption from each country, as a share of their customs value. It applies the rates in force, additional duties such as Section 301, 232 and IEEPA included and claimed trade-agreement preferences netted out, so it is an observed rate rather than a statutory one. It is an estimate, not duty collected: antidumping and countervailing duties, fees and later refunds are not in it. YoY compares year-to-date value with the same months last year.