Sourcing real-time clock ICs from China
Real-time clock integrated circuits from China carry 0% UK duty under heading 8542, with no trade remedies recorded. Confirm the code for the actual chip; a clock module needs a separate classification check. Component paperwork supports finished-product compliance. Cambridge China Bridge sources real-time clock integrated circuits.
UK duty on real-time clock chips
Heading 8542 covers electronic integrated circuits. For standalone real-time clock chips, check the other integrated circuit lines. The table also includes conditional alternatives for multi-component devices and processors or controllers combined with clock circuits; these are not interchangeable classifications. Assembled clock modules need a separate check. See the wider integrated circuits guide.
Read from the UK Trade Tariff on 30 September 2026, all listed lines carried 0% duty for goods from China. The supplied tariff record lists no anti-dumping or countervailing duties, suspensions or attached import controls. Import VAT is separate from customs duty.
Give your customs broker the manufacturer's datasheet, functional description and package details to confirm the commodity code. Specify whether the shipment contains bare chips or assembled boards, and whether the device is a standalone clock or a combined controller.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Other integrated circuits, including standalone clock chips where applicable | 8542 39 90 00 | 0% | None |
| Other multi-component integrated circuits meeting the chapter note | 8542 39 11 00 | 0% | None |
| Other integrated circuits meeting the chapter note, excluding multi-component types | 8542 39 19 00 | 0% | None |
| Other processors and controllers, including those combined with clock circuits | 8542 31 90 00 | 0% | None |
Specify timekeeping and backup behaviour
Specify the manufacturer, complete part number, revision, package, pin assignment and communications interface. Agree supply voltage, operating temperature range, timing accuracy across that range and backup current against the datasheet. State whether the oscillator and crystal are integrated or external, and include alarm outputs, calendar behaviour and oscillator-stop indication where needed.
Approve samples in your actual circuit. Test initialisation, register access, clock drift, alarm operation and transfer between the main and backup supplies. Ask for part-specific hazardous-substance declarations. Supplier assurances do not replace the finished-product manufacturer's determination of compliance with the hazardous-substance restrictions.
Worked duty example
Illustrative example, not a quote: 50,000 real-time clock chips on reels, illustrative order under 8542 39 90 00, invoiced at £40,000 free on board, with £600 of freight and insurance to the UK. The customs value is £40,600. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £40,600, so it is £8,120. 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 chip markings, package dimensions, pin orientation and reel labels to the approved part; retain manufacturer traceability, date codes and lot records.
Timekeeping: test sample devices against the datasheet and approved circuit, including clock drift, calendar transitions, register retention and alarm outputs.
Backup supply: check switchover, backup current and recovery after the main supply returns; confirm that the clock continues running as specified.
Handling: inspect protective packaging, moisture barrier seals and humidity indicators where specified; check bent leads, solderability and signs of remarking or recycled stock.
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What goes wrong
A replacement chip can fit the footprint yet use different registers, alarm logic or backup behaviour. A sample that communicates correctly may still lose time after power removal or drift outside the agreed temperature range. Approve substitutions through circuit testing before accepting the shipment.
Remarked parts and mixed lots undermine traceability. Damaged moisture protection can cause assembly failures, while unsuitable crystal loading can produce timing errors even with a genuine chip. Keep samples and test records by lot, and investigate the chip and surrounding circuit together.
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.
Frequently asked questions
What is the UK import duty on real-time clock chips from China?
The supplied tariff record shows 0% duty for heading 8542 lines, with no anti-dumping or countervailing duties. Import VAT is separate.
Which commodity code covers a real-time clock chip?
Check 8542 39 90 00 for a standalone clock chip. Multi-component devices and combined controllers may need another line. Confirm using the datasheet; do not automatically apply a chip code to a module.
Do real-time clock chips need UKCA marking?
Confirm with the relevant authority whether UKCA marking applies to the supplied component. Check the applicable hazardous-substance, electrical safety and electromagnetic compatibility rules for the finished product, and obtain part-specific supporting documents.
How do I check that the clock works on backup power?
Test approved samples in your circuit: remove the main supply, check continued timekeeping and backup current, then restore power and verify retained registers and alarm behaviour against the datasheet.