Sourcing PCR master mixes from China

Zero duty and intended-use classification

Read from the UK Trade Tariff on 1 October 2026, heading 3822 covers prepared diagnostic or laboratory reagents, including kits, and certified reference materials. The table shows potentially relevant diagnostic and laboratory lines, not interchangeable codes for every PCR master mix. Select the line from the finished product's composition and intended use.

All supplied lines carry 0% duty for goods from China, with no anti-dumping or countervailing measure and no suspension recorded. For 3822 90 00 00, the UK Trade Tariff attaches veterinary control and an ozone-depleting-substance restriction. If that line is proposed, ask your customs broker to confirm the requirements for the Chinese formulation, including any animal-derived stabiliser; do not assume these controls apply to every mix.

Confirm the formulation and intended use before choosing the commodity code. See the diagnostic and laboratory reagents guide for the wider heading. Zero duty does not remove import VAT; the duty and VAT guide explains the calculation.

Specify the PCR formulation and intended use

State whether the mix is for endpoint PCR, quantitative PCR or reverse-transcription PCR. Agree the polymerase, hot-start method, supplied concentration, buffer and magnesium composition, nucleotide content, dye or probe compatibility, reference dye and whether reverse transcriptase is included. Identify primers, probes and water that the buyer must supply separately.

Ask for compatibility data using your instrument, reaction protocol and representative sample types. Agree pack size, usable reaction yield, storage conditions, remaining shelf life and acceptable freeze-thaw handling. Obtain the batch certificate of analysis and stability evidence.

For sale as a diagnostic reagent in Great Britain, confirm with MHRA whether the product is a medical device and which UKCA or CE marking, UK Responsible Person and MHRA registration requirements apply before ordering. For research-only reagents, confirm appropriate research-use labelling and any restrictions on diagnostic marketing with MHRA.

Worked duty example

Illustrative example, not a quote: 500 packs of PCR master mix, illustrative order only under 3822 19 00 90, invoiced at £5,000 free on board, with £300 of freight and insurance to the UK. The customs value is £5,300. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £5,300, so it is £1,060. 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 formulation, supplied concentration, component list and lot number to the approved sample and order.

Performance: compare batch results with the agreed protocol, including positive controls, no-template controls and repeatability; for quantitative mixes, review amplification curves and dye compatibility.

Transport: check temperature-logger records against the supplier's validated shipping conditions, seals, leakage and the remaining shelf life.

Documents: match labels, storage instructions and the batch certificate to the delivered lot. For diagnostic products, check the agreed marking, registration and UK Responsible Person details.

What goes wrong

A mix can perform well in the factory's demonstration yet give weak amplification, background signal or inconsistent results with the buyer's samples. Missing reference dye, an unsuitable buffer or a changed enzyme can undermine a previously accepted protocol. Agree acceptance criteria using your own assay before approving the production formulation.

Temperature excursions, repeated thawing, leaking tubes and short expiry dates can make an otherwise acceptable batch unusable. Inspect the shipment and review the logger before releasing stock. Use the inspection guide to define the receipt checks and evidence to retain.

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.