Sourcing limestone flour from China

Duty on ground natural limestone flour

Heading 2521 covers limestone flux and limestone and other calcareous stone of a kind used to manufacture lime or cement. This guide focuses on ground natural limestone flour. The supplied tariff facts contain only one commodity line. See the limestone flux guide for the wider heading.

Read from the UK Trade Tariff on 29 September 2026, commodity code 2521 00 00 00 carries 0% duty for goods from China. The supplied facts list no anti-dumping or countervailing duty and no suspension.

The tariff attaches import and export waste controls. For imports into England subject to notification controls, the exporter must apply for consent to the competent authority in the country of dispatch. Ask your customs broker to confirm the requirement for your shipment from China, including whether the material is waste. Confirm the commodity code using its composition, processing and intended use.

Specify the mineral and the grind

Describe the product as ground natural limestone flour for your stated industrial application. Specify quarry source, calcium carbonate content, magnesium and silica content, particle-size distribution, coarse residue, moisture, whiteness where relevant, and bulk density. Agree test methods and acceptance criteria against a retained sample.

Ask the mill to disclose coatings, additives and blending. Specify bag construction, moisture protection, batch marking and the discharge arrangement for your equipment. Trial the powder in your process before approving production.

Employers must plan, manage and monitor the use of substances hazardous to health. Include dusty bag opening, sampling and powder transfer in your handling review.

Worked duty example

Illustrative example, not a quote: Illustrative order: 25 tonnes of ground natural limestone flour under 2521 00 00 00, invoiced at £2,400 free on board, with £1,200 of freight and insurance to the UK. The customs value is £3,600. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £3,600, so it is £720. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Identity: match the quarry and mill records, batch markings and analysis certificate to the order.

Grading: test representative batch samples for particle-size distribution and coarse residue against the agreed method.

Composition: compare carbonate content, magnesium, silica, moisture and colour with the specification and retained sample.

Arrival: check for torn bags, powder leakage, damp lumps and contaminated pallets; retain samples before using the batch. See quality inspection.

What goes wrong

A matching colour can hide a different grind or mineral composition. Coarse particles affect surface finish, variable moisture encourages caking, and changes in magnesium or silica can alter performance in the buyer's process. A sample from a different quarry bed or production batch may not represent the shipment.

Approve a production sample, agree how disputed results will be checked, and record batch identity through delivery. Keep leaking or damp bags separate while investigating. Ask for factory verification to check the mill's grinding, segregation and packing arrangements.

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.