HS 310540 Ammonium dihydrogenorthophosphate (monoammonium phosphate) and mixtures thereof with diammonium hydrogenorthophosphate (diammonium phosphate)
Quick Answer: Ammonium dihydrogenorthophosphate (monoammonium phosphate) and mixtures thereof with diammonium hydrogenorthophosphate (diammonium phosphate) imported under HS 310540 enters the UK at 6.00% ad valorem, the US duty-free, and the EU with rates varying by specific product composition. This classification specifically covers diammonium phosphate (DAP) and monoammonium phosphate (MAP), commonly used as fertilizers. Importers should verify specific EU tariff rates as they are not uniformly listed as "N/A" in all databases. CustomTariffs aggregates this data, highlighting the importance of checking destination country tariffs for accurate landed cost calculations.
What Are the Import Duty Rates?
🇬🇧 United Kingdom
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 3105400000 | 6.00 % | — | — |
🇪🇺 European Union (TARIC)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 3105400000 | — | — | — |
🇺🇸 United States (HTSUS)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 31054000 | Free | — | — |
| 3105400010 | — | — | ["t"] |
| 3105400050 | — | — | ["t"] |
Duty rates sourced from the USITC (US International Trade Commission) Harmonized Tariff Schedule (HTS) (accessed 2/22/2026), EU TARIC – DG TAXUD (Directorate-General for Taxation and Customs Union) (accessed 2/22/2026), and UK Trade Tariff – HMRC (His Majesty's Revenue and Customs) (accessed 2/22/2026).
Data compiled and presented by HSRates.
How Has Trade Volume Developed?
Trade Volume 2023
How to Classify This HS Code?
What products does HS 310540 cover?
This subheading covers ammonium dihydrogenorthophosphate, commonly known as monoammonium phosphate (MAP), and diammonium hydrogenorthophosphate, known as diammonium phosphate (DAP), as well as mixtures of these two compounds. According to the World Customs Organization (WCO) Harmonized System Explanatory Notes, these are specific types of mineral or chemical fertilizers containing phosphorus and nitrogen. The US International Trade Commission (USITC) Harmonized Tariff Schedule (HTS) and the EU's TARIC database confirm this scope, focusing on these distinct chemical entities and their combinations for agricultural use.
What falls outside HS 310540?
The following products are excluded from HS 310540: other ammonium phosphates not specifically identified (e.g., those with additional elements or in different chemical forms), fertilizers containing other active ingredients in addition to MAP or DAP, and products that are not solely or principally used as fertilizers. For instance, technical grade MAP or DAP used in industrial processes, or compound fertilizers where MAP/DAP is a component but not the sole or primary defining characteristic, would be classified elsewhere, potentially under broader fertilizer headings or industrial chemical codes.
What are common classification mistakes for HS 310540?
A common error is misclassifying mixtures of MAP and DAP with other fertilizer components or inert materials. According to General Rule of Interpretation (GRI) 3(b) of the Harmonized System, mixtures are often classified according to the component that gives them their essential character. If a product contains MAP or DAP but is predominantly composed of other nutrients like potassium or micronutrients, it might fall under a different subheading for compound fertilizers, such as 3105.20, rather than 3105.40.
How should importers classify products under HS 310540?
The correct procedure for classifying products under HS 310540 involves a detailed examination of the product's chemical composition and intended use. Importers and customs brokers must verify that the product is indeed ammonium dihydrogenorthophosphate, diammonium hydrogenorthophosphate, or a mixture thereof, and that its primary function is as a fertilizer. Consulting the product's Safety Data Sheet (SDS) and the official tariff schedules of the importing country, such as the USITC HTS or the UK Trade Tariff, is crucial for accurate determination.
How is the duty calculated for products under HS 310540?
A shipment of 10 metric tons of Diammonium Phosphate (DAP) declared at a customs value of $5,000 USD would attract a US duty of $0.00. This is because the Most Favored Nation (MFN) duty rate for HS code 3105.40 in the USITC Harmonized Tariff Schedule is 0% ad valorem. Therefore, the calculation is 0% × $5,000 USD = $0.00 USD. This reflects the duty-free status for this fertilizer under the standard US tariff regime.
Which trade agreements reduce duties for HS 310540?
Several free trade agreements may reduce the applicable duty rate for HS 310540, including the United States-Mexico-Canada Agreement (USMCA), which can result in a "Free" duty rate for originating goods from Canada and Mexico. Additionally, the Generalized System of Preferences (GSP) may offer reduced or free entry for qualifying products from certain developing countries. To claim preference under USMCA, a compliant origin declaration is required; for GSP, a GSP Form A or a self-certified origin statement may be necessary, depending on the beneficiary country and importing jurisdiction.
```Which HS Codes Are Related?
Not the right code? Search all HS codes to find the correct tariff classification.
FAQ
What are the import duty rates for HS code 310540 (Ammonium dihydrogenorthophosphate and mixtures thereof)?
For imports into the United States, the Most Favored Nation (MFN) duty rate for HS code 310540 is 6.00% ad valorem. However, under the Generalized System of Preferences (GSP), many developing countries can import this product duty-free. It is crucial to verify the specific country of origin and any applicable trade agreements to determine the correct preferential duty rate. For example, imports from a GSP beneficiary country might be free, while imports from a non-GSP country would be subject to the 6.00% MFN rate. Always consult the latest Harmonized Tariff Schedule of the United States (HTSUS) for the most current rates.
How is the import duty for HS code 310540 calculated, and can you provide an example?
The duty for HS code 310540 is typically calculated on an ad valorem basis, meaning it's a percentage of the declared value of the goods. For instance, if the MFN duty rate is 6.00% and you import 10,000 kilograms of ammonium dihydrogenorthophosphate valued at $5,000 USD, the duty calculation would be: Value of goods = $5,000 USD. Duty rate = 6.00%. Duty amount = $5,000 USD * 0.06 = $300 USD. If the tariff specified a per-unit duty (e.g., $0.05 per kg), the calculation would be: Quantity = 10,000 kg. Per-unit duty = $0.05/kg. Duty amount = 10,000 kg * $0.05/kg = $500 USD. Always confirm the specific duty basis (ad valorem, specific, or compound) from the HTSUS.
What are the key classification criteria for goods falling under HS code 310540?
HS code 310540 specifically covers 'Ammonium dihydrogenorthophosphate (monoammonium phosphate) and mixtures thereof with diammonium hydrogenorthophosphate (diammonium phosphate)'. The primary classification criteria are the chemical composition and the presence of these specific ammonium phosphate compounds. Monoammonium phosphate (MAP) has the chemical formula NH₄H₂PO₄, and diammonium phosphate (DAP) has the formula (NH₄)₂HPO₄. Mixtures containing both are also included. Goods that are solely MAP or DAP, or mixtures where these are the principal components, will fall under this code. It is essential to have a chemical analysis or product specification sheet to confirm the composition aligns with the heading's description. Fertilizers containing these compounds along with other substances might be classified elsewhere.
What documentation is typically required for importing goods classified under HS code 310540?
When importing goods under HS code 310540, standard import documentation is required, including a commercial invoice, packing list, and bill of lading or air waybill. Additionally, a Certificate of Origin may be necessary to claim preferential duty rates under trade agreements. Given that these are fertilizers, importers may need to provide documentation confirming compliance with any relevant agricultural or environmental regulations of the importing country. For the US, this might include declarations related to the U.S. Department of Agriculture (USDA) if specific import permits or certifications are mandated for such chemical fertilizers. Always check the specific import requirements of the destination country.
Which common trade agreements might offer preferential duty rates for HS code 310540, and how can importers verify eligibility?
The United States has various trade agreements, including the Generalized System of Preferences (GSP) which benefits many developing countries, and specific Free Trade Agreements (FTAs) with countries like Canada (USMCA), Mexico (USMCA), and others. Many of these agreements can provide duty-free or reduced-duty entry for products classified under HS code 310540, provided the goods meet the rules of origin stipulated in the respective agreement. To verify eligibility, importers must obtain a Certificate of Origin from the exporter, which certifies that the goods meet the origin requirements. This certificate, along with the specific tariff schedule of the importing country (e.g., HTSUS for the US), will detail the preferential rates and conditions. For example, if importing from a country that is a beneficiary of the GSP program, the duty rate could be Free.