Sourcing potato protein isolate from China

Duty on plain potato protein isolate

Read from the UK Trade Tariff on 1 October 2026, heading 3504 covers protein substances and derivatives not elsewhere specified, alongside peptones and hide powder. For plain potato protein isolate, use 3504 00 90 99 as the proposed line for broker confirmation. The table repeats this line for different buying specifications; these are not separate tariff subdivisions.

The supplied tariff snapshot shows 2% duty for goods from China and no anti-dumping or countervailing measure. The suspension on this line covers zein, not potato protein. It attaches veterinary and organic import controls. Ask the broker to confirm whether veterinary controls apply to the actual composition. For organic food imports from China, confirm with your organic control body whether a Great Britain certificate of inspection is required; the exporter’s control body issues it.

Give the broker the ingredient list, extraction process, intended use and specification to confirm the commodity code. Added flavours, sweeteners or other ingredients need a fresh classification check. See the rice protein isolate guide for wider heading context.

Specify the process and potato protein function

Ask whether the protein is heat-coagulated, recovered without heat coagulation or further hydrolysed. Obtain a process description rather than accepting an isolate label as proof of food-market status. Novel foods need authorisation before being placed on the market in Great Britain. Confirm the status of the exact ingredient and intended use before ordering.

Specify protein content on a stated basis, the nitrogen conversion factor, moisture, ash, particle size, colour and taste. Agree tests for glycoalkaloids and microbiological quality. For beverages, trial dispersion and sediment; for bakery products, trial binding, foaming and the effect of heating. Retain the approved sample and agree batch acceptance criteria.

Worked duty example

Illustrative example, not a quote: Illustrative order: 2 tonnes of plain potato protein isolate powder under 3504 00 90 99, invoiced at £16,000 free on board, with £2,000 of freight and insurance to the UK. The customs value is £18,000. Duty at 2% is £360. Import VAT at 20% is charged on the customs value plus duty, £18,360, so it is £3,672. Import taxes total £4,032; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £360 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Identity: match the potato source, process description and ingredient declaration to the approved specification; check for starch or other protein substitutions.

Batch analysis: match the certificate to the delivered lot and independently check protein, moisture, glycoalkaloids and agreed microbiological criteria.

Function: compare colour, odour, dispersion and performance in your actual recipe with the retained sample.

Packing: check seals, liners, lot identification and evidence of damp or caking; reconcile delivered bags with shipment records.

What goes wrong

A certificate can report protein on a dry basis while the buyer compares it with the powder as delivered. Heat treatment can also change solubility and foaming, so matching protein content does not guarantee matching performance. Quarantine discrepant lots and investigate against the retained sample.

A food-grade sales description does not establish novel-food status, and the zein suspension cannot be claimed for potato protein. Resolve market status and tariff treatment before dispatch. Organic paperwork must match the shipment rather than merely showing that the factory holds an organic certificate.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For repeat volumes, see container programmes.