Chapter 31
Fertilizers
37 tariff lines · 29 filing-ready 10-digit codes · codes begin with 31
Chapter 31 of the US Harmonized Tariff Schedule covers fertilizers. Every code in this chapter starts with the digits 31. Work down the nested list below: the bold headings are broad categories, and the 10-digit statistical codes underneath them are what you actually declare to US Customs. Duty rates shown are the general (Column 1) rates that apply to most trading partners.
Codes in Chapter 31
| HTS code | Description | Level | General duty rate |
|---|
| HTS code | Description | Level | General duty rate |
|---|---|---|---|
| 3102.10.00 | Urea, whether or not in aqueous solution | 8-digit subheading | Free |
| 3102.10.00.10 | Solid urea | 10-digit statistical code | |
| 3102.10.00.30 | Diesel exhaust fluid (DEF) of a kind meeting ISO 22241 | 10-digit statistical code | |
| 3102.10.00.50 | Other | 10-digit statistical code | |
| 3102.21.00.00 | Ammonium sulfate | 10-digit statistical code | Free |
| 3102.29.00.00 | Other | 10-digit statistical code | Free |
| 3102.30.00.00 | Ammonium nitrate, whether or not in aqueous solution | 10-digit statistical code | Free |
| 3102.40.00.00 | Mixtures of ammonium nitrate with calcium carbonate or other inorganic nonfertilizing substances | 10-digit statistical code | Free |
| 3102.50.00.00 | Sodium nitrate | 10-digit statistical code | Free |
| 3102.60.00.00 | Double salts and mixtures of calcium nitrate and ammonium nitrate | 10-digit statistical code | Free |
| 3102.80.00.00 | Mixtures of urea and ammonium nitrate in aqueous or ammoniacal solution | 10-digit statistical code | Free |
| 3102.90.01.00 | Other, including mixtures not specified in the foregoing subheadings | 10-digit statistical code | Free |
| HTS code | Description | Level | General duty rate |
|---|---|---|---|
| 3103.11.00.00 | Containing by weight 35 percent or more of diphosphorous pentaoxide (P2O5) | 10-digit statistical code | Free |
| 3103.19.00.00 | Other | 10-digit statistical code | Free |
| 3103.90.01.00 | Other | 10-digit statistical code | Free |
| HTS code | Description | Level | General duty rate |
|---|---|---|---|
| 3104.20.00 | Potassium chloride | 8-digit subheading | Free |
| 3104.20.00.10 | Containing not more than 62 percent by weight of potassium oxide (K2O) | 10-digit statistical code | |
| 3104.20.00.50 | Containing more than 62 percent by weight of potassium oxide (K2O) | 10-digit statistical code | |
| 3104.30.00.00 | Potassium sulfate | 10-digit statistical code | Free |
| 3104.90.01.00 | Other | 10-digit statistical code | Free |
| HTS code | Description | Level | General duty rate |
|---|---|---|---|
| 3105.10.00.00 | Products of this chapter in tablets or similar forms or in packages of a gross weight not exceeding 10 kg | 10-digit statistical code | Free |
| 3105.20.00.00 | Mineral or chemical fertilizers containing the three fertilizing elements nitrogen, phosphorus and potassium | 10-digit statistical code | Free |
| 3105.30.00.00 | Diammonium hydrogenorthophosphate (Diammonium phosphate) | 10-digit statistical code | Free |
| 3105.40.00 | Ammonium dihydrogenorthophosphate (Monoammonium phosphate) and mixtures thereof with diammonium hydrogenorthophosphate (Diammonium phosphate) | 8-digit subheading | Free |
| 3105.40.00.10 | Ammonium dihydrogenorthophosphate (Monoammonium phosphate) | 10-digit statistical code | |
| 3105.40.00.50 | Other | 10-digit statistical code | |
| 3105.51.00.00 | Containing nitrates and phosphates | 10-digit statistical code | Free |
| 3105.59.00.00 | Other | 10-digit statistical code | Free |
| 3105.60.00.00 | Mineral or chemical fertilizers containing the two fertilizing elements phosphorus and potassium | 10-digit statistical code | Free |
| 3105.90.00 | Other | 8-digit subheading | Free |
| 3105.90.00.10 | Potassium nitrate-sodium nitrate mixtures | 10-digit statistical code | |
| 3105.90.00.50 | Other | 10-digit statistical code |
Not sure which line applies?
Classification follows the General Rules of Interpretation: the most specific description wins, and you must use a 10-digit statistical code on the entry. When two lines look equally plausible, a CBP binding ruling is the only way to be certain.
Source: USITC Harmonized Tariff Schedule, 2026 Basic Edition, Revision 16. Rate text is reproduced verbatim from the official export; category paths and duty estimates are derived.
Data loaded August 18, 2026.Check this chapter on hts.usitc.govReport an errorHow this data is built