Sourcing guanidine thiocyanate from China

Provisional classification and zero duty

Read from the UK Trade Tariff on 1 October 2026, heading 2925 covers carboxyimide-function and imine-function compounds. The residual imine line 2925 29 00 90 carries 0% duty for goods from China, with no anti-dumping or countervailing duty and no suspension recorded. It is a provisional classification for unformulated guanidine thiocyanate solid. The table repeats this line for purchasing specifications, rather than showing separate tariff subdivisions.

The supplied tariff record attaches Veterinary control to this line and also records Export control on dangerous chemicals and Export control - Waste. The veterinary requirement for this particular product has not been established: ask your customs broker to confirm it using the composition and manufacturing origin. Ask the broker to check the recorded export controls before arranging any return shipment.

Confirm the commodity code using the chemical identity, composition and physical form. Do not assume a formulated extraction buffer takes the solid chemical's code. See the guanidine hydrochloride guide for the wider heading context.

Specify assay and suitability for your extraction

Specify guanidine thiocyanate explicitly, including the chemical identity reference, solid form, intended use, assay method, water content and agreed impurity tests. For nucleic-acid extraction, ask for evidence supporting the supplier's nuclease-free claim and test a sample in your actual extraction process. Agree dissolution and solution appearance checks. A grade name alone does not define acceptance.

For Great Britain, check UK REACH registration coverage when annual imports of the substance reach 1 tonne. Classification and labelling must be carried out by someone with the scientific competence to do so. Chemicals must be correctly labelled and packaged before market placement. A safety data sheet is required when a hazardous chemical is supplied for workplace use.

Worked duty example

Illustrative example, not a quote: 15 kg of reagent-grade guanidine thiocyanate solid, illustrative only under 2925 29 00 90, invoiced at £2,500 free on board, with £800 of freight and insurance to the UK. The customs value is £3,300. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £3,300, so it is £660. 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 product name and chemical identity reference across the order, container labels, safety data sheet and batch certificate; distinguish thiocyanate from hydrochloride.

Batch results: check that the certificate belongs to the delivered batch and reports the agreed assay, water and impurity tests with their methods.

Application: test dissolution, solution appearance and extraction performance against the approved sample; verify any agreed nuclease testing.

Packaging: inspect seals, liners and closures for damage or powder leakage; record caking and match container batch references to the certificate.

What goes wrong

Buying on assay alone leaves application performance untested. A batch can meet the agreed assay while failing your dissolution, impurity or nuclease specification. Confusion between guanidine salts and a certificate copied from another batch are further acceptance risks. Define rejection criteria before ordering and retain a sample linked to the delivered batch.

Keep a leaking container or an unexplained batch discrepancy out of use while you investigate. Compare the received material with the approved sample and request batch-specific results rather than accepting a replacement certificate without explanation.

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.