Sourcing replacement flask stoppers from China

Duty on replacement vacuum flask stoppers

Heading 9617 covers complete vacuum flasks and other vacuum vessels, and their parts other than glass inners. This guide concerns replacement stopper assemblies. The tariff extract contains a single commodity line, so the table shows that line once. See the vacuum flasks and tumblers guide for complete vessels.

Read from the UK Trade Tariff on 30 September 2026, commodity code 9617 00 00 00 carries 0% duty for goods from China. The supplied extract lists no anti-dumping or countervailing duty, suspensions or attached import controls.

Give your customs broker the stopper drawing, material list, photographs and details of the vacuum flask it fits. Confirm that the assembly belongs under this line before declaring it. Our commodity code guide explains how to check the classification.

Specify the stopper against the actual flask

Send the factory an approved flask and stopper sample. Specify the thread profile, neck engagement, sealing face, insertion depth, gasket material and hardness, and whether the stopper screws out or pours through a button-operated valve. State whether replacement seals are included and how the assembly comes apart for cleaning.

Ask the relevant authority to confirm the food-contact requirements for stopper plastics and seals, including requirements concerning constituent transfer into drinks that could endanger health. Ask for the material specification and migration reports covering the finished assembly and intended drink temperatures. The food-contact materials guide explains the evidence to request.

Consumer products sold in Great Britain must be safe in normal or reasonably foreseeable use. Agree tests for secure closure, controlled pouring and valve operation with hot drinks. Check cleaning instructions against the actual assembly before approving the pack.

Worked duty example

Illustrative example, not a quote: Illustrative order: 10,000 replacement push-button vacuum flask stoppers under 9617 00 00 00, invoiced at £32,000 free on board, with £2,500 of freight and insurance to the UK. The customs value is £34,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £34,500, so it is £6,900. 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

Fit: try production samples on the intended flask models. Check smooth thread engagement, full seating and removal without cross-threading or excessive force.

Sealing: check gasket position and compression. With the stopper closed, test filled flasks upright, on their side and inverted, then repeat after opening and cleaning.

Pouring mechanism: check button travel, valve return, flow and drips after closing. Look for loose components, sharp moulding flash and inaccessible drink residue.

Materials and packing: match plastics, seals and reports to the approved specification. Check compatibility descriptions, cleaning instructions and included seals during quality inspection.

What goes wrong

A stopper can look right yet leak because its thread or sealing face differs from the original. A gasket may roll out of its groove, while a poorly returning valve can keep dripping after the button closes. Approve fit and leak tests on the actual flask before accepting production.

Material substitutions can undermine the food-contact evidence. Seals may taint drinks, and enclosed valve passages can retain residue after washing. Compare production parts with the approved assembly, repeat cleaning and pouring checks, and investigate odour or leakage before releasing stock.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For own-brand ranges, see sourcing for brands.