Sourcing battery-powered data loggers from China

Zero duty on the relevant logger lines

Read from the UK Trade Tariff on 30 September 2026, all the selected lines within heading 9025 carried 0% duty on goods from China. No anti-dumping or countervailing duty, or suspension, was listed. The heading covers temperature and humidity instruments, whether recording or not. Import VAT is normally 20%; see UK import duty and VAT.

For classification, distinguish temperature-only instruments from combined temperature and humidity instruments. The semiconductor sensor line has specific construction and incorporation conditions and should not be used simply because a finished logger contains a sensor. Parts are also separate from finished instruments. Confirm the commodity code using the complete functions, sensor construction and intended use.

The UK Trade Tariff lists a supplementary import unit for the selected semiconductor sensor line and a mercury export control for the electronic instrument and sensor lines. Ask your customs broker to confirm the declaration unit and control requirements relevant to your transaction. Mercury import controls are attached to liquid-filled and non-electronic lines outside this selection; confirm their requirements if supplying those goods. See the wider thermometer and hygrometer guide.

Specify the measurements and the recording behaviour

Specify temperature and humidity ranges, accuracy across the working range, resolution, response time and calibration evidence. Agree the recording interval, memory capacity, start and stop method, alarm behaviour and what happens when memory fills. State whether the logger is reusable, whether its battery can be replaced, and whether probes are internal or external.

Agree the battery chemistry and expected operating conditions, including cold storage. Specify the download connection, supported computer systems, offline access, file format, time zone and identification of each logger in exported records. Test the sample with your own computer and workflow before approving production.

For Great Britain, check electromagnetic compatibility evidence for non-radio models. CE marking continues to be recognised for electromagnetic compatibility conformity. Finished electrical equipment is within the hazardous-substance rules unless specifically excluded. Wireless models fall under the radio equipment rules unless excluded. Ask for model-specific compliance documents through testing and certification.

Electrical-equipment producers must register annually. Battery registration depends on the battery type and quantity placed on the market. Confirm your arrangements for both the logger and its supplied battery before resale, and agree how the factory will provide equipment and battery weight records.

Worked duty example

Illustrative example, not a quote: Illustrative reseller order: 1,500 battery-powered temperature and humidity data loggers under 9025 80 40 89, invoiced at £24,000 free on board, with £1,500 of freight and insurance to the UK. The customs value is £25,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £25,500, so it is £5,100. 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

Accuracy: compare temperature and humidity readings with calibrated references across the agreed operating range. Match calibration records to the sampled logger identities and check humidity recovery after exposure to damp conditions.

Recorded data: run a complete recording and download cycle. Check timestamps, recording intervals, alarm events, logger identification and exported values against the readings observed during the test.

Battery and memory: check cell chemistry, polarity, contacts and covers. Test low-battery behaviour, memory-full behaviour and whether stored records remain accessible after battery replacement or depletion.

Build and documents: check probe strain relief, display segments, seals and the agreed moisture protection. Match the model, markings, compliance documents and English instructions to the delivered goods. Arrange quality inspection around these functional checks.

What goes wrong

An accurate live display can hide a recording failure. Incorrect clock settings, overwritten memory, missed start commands or download software that does not work on the buyer's computer can leave unusable records. Approve exported files from an actual sample run, including the logger identity and alarm history.

Humidity sensors can stick after condensation, while cold conditions can expose weak batteries, poor contacts or fading displays. Check recovery and recording under the intended conditions. Agree that changes to sensors, batteries, firmware or download software require your review before shipment.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For components and parts, see sourcing for manufacturers.