Sourcing doped lithium niobate wafers from China

Duty on doped lithium niobate wafers

Heading 3818 covers chemical elements doped for electronics in discs, wafers or similar forms, and chemical compounds doped for electronics. Doped lithium niobate wafers fall within the other-compounds line, subject to confirmation of their composition and intended use. The table describes buying variants within the same commodity line.

Read from the UK Trade Tariff on 1 October 2026, the supplied record shows 0% duty for goods from China under 3818 00 90 00. It lists no anti-dumping or countervailing duty, suspension or attached import control for this line.

Give your customs broker the composition, dopant details, wafer form and intended use to confirm the commodity code. The code must appear on the import declaration. For the wider heading, see the doped gallium arsenide wafer guide.

Specify the dopant, crystal cut and surface

Specify the dopant species and concentration, including the basis used to express it. Agree crystal composition, cut direction, cut angle and tolerance, diameter, thickness, thickness variation, flatness, bow and edge finish. State whether polishing is required on a single face or both faces, and define surface roughness, scratch and chip acceptance criteria.

Ask for batch-linked composition and orientation reports, measurement methods and a sample tested in your intended process. UK REACH generally covers substances on their own, in mixtures and in articles. For a substance you have not previously imported, assess whether registration is required. Establish how the supplied wafer is treated under REACH rather than assuming its tariff code settles that question.

Worked duty example

Illustrative example, not a quote: Illustrative trial batch of magnesium-doped lithium niobate wafers under 3818 00 90 00, invoiced at £3,000 free on board, with £600 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: compare the dopant, concentration basis, crystal cut and batch identifiers with the purchase specification and supplier reports.

Geometry: measure diameter, thickness, thickness variation and bow against agreed tolerances; check the orientation reference and edge finish.

Surface: inspect polished faces for scratches, pits, contamination, chips and cracks; compare roughness measurements with the agreed method.

Packing: check wafers are separated and restrained in clean carriers, inspect seals and cushioning, and photograph damage before unpacking further. Agree sampling through the quality inspection guide.

What goes wrong

A wafer can match the nominal material name but have the wrong dopant concentration basis, crystal cut or polished face. Scratches, edge chips, bow and contamination can also make it unsuitable for the buyer's process. A generic report without a matching batch identifier cannot establish the delivered lot's properties.

Approve a sample against the actual process, record the acceptance methods in the order, and compare arrival samples with that baseline before releasing the batch. Keep suspect wafers separate while the supplier investigates.

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.