Sourcing TMAH from China
Tetramethylammonium hydroxide from China carries 0% to 6% UK duty: the named aqueous solution has a suspension, while other grades need classification checks. Chemicals must be correctly labelled and packaged before sale in Great Britain. Cambridge China Bridge sources tetramethylammonium hydroxide.
Named solution suspended to 0%; standard duty 6%
Read from the UK Trade Tariff on 1 October 2026, heading 2923 covers quaternary ammonium salts and hydroxides, lecithins and other phosphoaminolipids. Tetramethylammonium hydroxide aqueous solution containing 25% (± 0,5%) by weight is named under 2923 90 00 10. Its standard China duty is 6%, with an autonomous suspension to 0%. The suspension footnote excludes mixtures, preparations and products made up of different components containing the substance.
The residual line 2923 90 00 90 carries standard duty of 6%. Its recorded suspension names other substances, so do not apply it to tetramethylammonium hydroxide. Neither relevant line records anti-dumping or countervailing duty. Both attach dangerous-chemical and waste controls labelled as export controls. Confirm with your customs broker what, if anything, these entries require for your shipment from China.
Give your broker the chemical identity, solvent, concentration, additives and batch analysis before confirming the commodity code. Do not assume every concentration or formulated developer uses the named solution line. Only the named and residual lines are relevant here; see the wider heading guide for other products.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Tetramethylammonium hydroxide aqueous solution, 25% (± 0,5%) by weight | 2923 90 00 10 | 6% | None |
| Other quaternary ammonium hydroxides, subject to composition checks | 2923 90 00 90 | 6% | None |
Specify concentration and metal impurities
Specify tetramethylammonium hydroxide by chemical identity, aqueous concentration by weight and intended process. State whether you need technical or electronic grade. For electronic use, agree individual metal impurity limits and the analytical method rather than accepting an undefined purity claim. Ask for batch-specific results and trial the supplied grade in your process.
Agree container material, closure, seal, batch identification and sampling arrangements. Check hazard labels against the English safety data sheet. Chemicals must be correctly labelled and packaged before being placed on the Great Britain market. Confirm your UK REACH position where annual substance imports reach one tonne or more.
Worked duty example
Illustrative example, not a quote: Illustrative order: one tonne of tetramethylammonium hydroxide aqueous solution outside the named concentration specification, subject to classification confirmation under 2923 90 00 90, invoiced at £2,500 free on board, with £1,800 of freight and insurance to the UK. The customs value is £4,300. Duty at 6% is £258. Import VAT at 20% is charged on the customs value plus duty, £4,558, so it is £911.60. Import taxes total £1,169.60; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £258 of duty. The import duty and VAT guide explains each step.
Inspection checklist
Identity: match the purchase specification, container labels, safety data sheet and certificate of analysis to the same substance, concentration and batch.
Concentration: have a laboratory check the delivered solution against the agreed assay and tolerance; do not rely solely on the supplier's nominal concentration.
Metal impurities: for electronic grade, compare batch results with the agreed individual limits and arrange independent testing where needed.
Packaging: check closures, seals, leaks and batch labels on arrival, and record any damaged containers before accepting the delivery.
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What goes wrong
A nominal concentration can conceal an out-of-specification batch, while an electronic-grade claim may lack evidence for individual metal impurities. An analysis certificate for a different lot cannot establish the quality of the delivered material. Agree acceptance criteria and hold material with unresolved identity, assay or contamination discrepancies.
Duty assumptions also fail when buyers use the named solution code for a different concentration or formulation. Have the broker check composition before shipment, and review the batch evidence before approving dispatch. Use the quality inspection guide to define the inspection scope.
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.
Frequently asked questions
What is the UK import duty on tetramethylammonium hydroxide from China?
The named solution under 2923 90 00 10 has standard duty of 6%, suspended to 0%. The residual line has standard duty of 6%; its recorded suspension names other substances.
Does every concentration qualify for the duty suspension?
No. The named line specifies an aqueous solution containing 25% (± 0,5%) by weight. Have your broker check other concentrations and formulations before using that code.
What should an electronic-grade batch certificate show?
The delivered batch identity, concentration, individual metal impurity results and analytical methods, checked against your agreed specification.
Do I need to check UK REACH before importing?
Yes. Confirm your UK REACH position where annual imports of the substance reach one tonne or more. Check the substance quantity rather than treating the entire solution as active chemical.