Sourcing phosphates and STPP from China
Sodium, potassium and calcium phosphates, sodium tripolyphosphate (STPP) and hypophosphites from China mostly pay 4% UK duty, with other calcium phosphates at 0% and several named substances suspended to 0%, and no anti-dumping duty. Food grades must meet additive specifications, and detergent phosphate content is restricted. Cambridge China Bridge sources phosphates.
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Mostly 4%
Read from the UK Trade Tariff on 27 September 2026, phosphinates and phosphonates, phosphates of mono- or disodium, potassium, dicalcium phosphate, triammonium and trisodium phosphates, sodium triphosphate and other polyphosphates carried 4% duty on goods from China, and other phosphates of calcium 0%, with no anti-dumping measure. Sodium hypophosphite (the monohydrate line and grades of 97% purity or more) and aluminium phosphinate are suspended to 0% until 31 December 2028, while calcium phosphinate (2835 10 00 40) pays 4% with no suspension, and dibasic sodium phosphate dihydrate and monobasic potassium phosphate can enter at 0% with document code 9Y11.
Mineral phosphate rock is in heading 2510, phosphoric acid in 2809 and fertilisers in chapter 31, so confirm the commodity code with the CAS number and grade. For the acid, see our phosphoric acid sourcing guide. For phosphorous acid, see our inorganic acid sourcing guide.
| Goods | Commodity code | Duty | Anti-dumping duty on China |
|---|---|---|---|
| Sodium hypophosphite of 97% purity or more | 2835 10 00 50 | 4%; suspended to 0% until 31 Dec 2028 | None |
| Calcium phosphinate of 98% purity or more | 2835 10 00 40 | 4% | None |
| Phosphates of mono- or disodium | 2835 22 00 00 | 4% | None |
| Phosphates of potassium | 2835 24 00 00 | 4% | None |
| Dicalcium phosphate | 2835 25 00 00 | 4% | None |
| Other phosphates of calcium | 2835 26 00 00 | 0% | None |
| Sodium tripolyphosphate (STPP) | 2835 31 00 00 | 4% | None |
Food, feed and detergent rules
Food-grade sodium, potassium and calcium phosphates and polyphosphates are additives E 339, E 340, E 341 and E 451 and must meet the purity criteria on the FSA register of authorised food additives, including limits on arsenic, lead and fluoride, so ask for the grade and a certificate of analysis per batch. Feed-grade dicalcium phosphate must meet the undesirable substances limits for animal feed. For related food-grade salt sourcing, see our sulphates and alums guide.
The retained detergents regulation limits phosphates and other phosphorus compounds in consumer laundry detergents and automatic dishwasher detergents, so STPP for those uses has to fit the product's permitted phosphorus content. Importers of one tonne or more a year need a UK REACH position. For alkali procurement, see our guide to caustic soda and caustic potash. For ammonia procurement, see our ammonia and ammonia solution guide.
Worked duty example
Take a hypothetical order of 40 tonnes of sodium tripolyphosphate, entered under 2835 31 00 00: £40,000 free on board plus £3,000 of freight and insurance gives a customs value of £43,000. The 4% duty on sodium tripolyphosphate comes to £1,720, and import VAT is 20% of £44,720, which is £8,944. If you are VAT-registered you normally reclaim the £8,944, leaving £1,720 as the real cost at the border. Step by step: UK import duty and VAT.
What goes wrong
Phosphates fail on grade, impurities and moisture. Technical grade is supplied against a food or feed order, fluoride, arsenic or heavy metals exceed the additive or feed limits, and STPP assay or phase content misses the specification so it performs badly in detergents or processed food. Powders cake in damp containers, and bags arrive without the grade, batch number or English labels.
Ask for a certificate of analysis per batch covering assay, fluoride, arsenic, lead and moisture, test the first delivery in a UK laboratory, check that food and feed grades come from plants with food safety or feed certification, check bag labels and batch numbers against the certificate, and use lined bags and dry containers.
Cambridge China Bridge sources food, feed and technical-grade phosphates and STPP, with grades and certificates agreed before shipment. See how we source industrial chemicals.
Related guides: Nitrides, hydrides and silicides from China.
Related guides: Sourcing borax and borates from China.
Frequently asked questions
What is the UK import duty on STPP from China?
Read from the UK Trade Tariff on 27 September 2026, sodium tripolyphosphate carried 4% duty from China, with no anti-dumping duty.
Are any phosphates at 0%?
Other phosphates of calcium are 0%, and sodium hypophosphite and named phosphinates are suspended to 0% until 31 December 2028.
Which E numbers cover phosphates?
E 339 sodium, E 340 potassium and E 341 calcium phosphates, and E 451 triphosphates.
Are phosphates in detergents restricted?
Yes. The retained detergents regulation limits phosphorus content in consumer laundry and dishwasher detergents.