HS 850431 · Small transformers (≤1 kVA)
Get the code right at quotation time, not at customs.
Misclassifying HS 850431 on the commercial invoice walks the cargo into the wrong duty rate, the wrong rebate column, and a customs hold that costs days of demurrage to clear. This page gives you the WCO heading, the product it most often covers, the China VAT export rebate rate, the US Section 301 status, the supplier provinces that ship it, and practitioner buying notes for first-time importers.
For an explanation of how the WCO Harmonized System is structured, what each digit means, and why misclassification is the most common landed-cost error first-time buyers make, see the HS code glossary entry.
Key facts
The numbers a buyer needs at the quotation stage. Verify each against the live source before invoicing; rates and rebate columns move.
| WCO heading | Other transformers, having a power handling capacity ≤1 kVA |
|---|---|
| Chapter | 85, Electrical machinery and equipment |
| Industry segment | Batteries and power |
| Chinese name | 小型变压器 |
| China VAT export rebate | 13% Source: China State Taxation Administration (国家税务总局), 2025 schedule. Subject to change. |
| US Section 301 | 25% Source: USTR Section 301 List 1 / 2 / 3 / 4. Verify against the current schedule. |
| Major Chinese supplier provinces | Guangdong, Zhejiang |
Buying notes
Small power transformers, signal transformers, and isolation transformers ≤1 kVA. Used in power supplies, audio equipment, telecom, and signal isolation. Foshan and Hangzhou run the bulk. Section 301 25%. Insulation class (B, F, H), regulation (load to no-load voltage drop), and saturation flux density are the spec axes.
Common end uses
The applications that drive most of the global tonnage under this code.
- Switching power supplies and chargers
- LED-driver isolation
- Audio amplifier output stages
- Telecom signal isolation and DAA
- Industrial control panels and instrumentation
Where to read next
For the structure of the HS / Harmonized System, what each digit means, and why misclassification costs landed-cost margin, see the HS code glossary entry.
Need a quote on this code? Send us the HS code, the destination port, and the tonnage and we will quote FOB China and CIF / DDP landed including the current Section 301 and rebate position.
Read next
Other codes in the same chapter and the references behind them
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HS 854141 Solar cells (PV modules and panels)
Chapter 85, Solar cells (PV modules and panels). China VAT rebate 13%.
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HS 854110 Diodes (other than photosensitive or LED)
Chapter 85, Diodes (other than photosensitive or LED). China VAT rebate 13%.
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HS 854121 Transistors with dissipation rate <1W
Chapter 85, Transistors with dissipation rate <1W. China VAT rebate 13%.
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HS 850610 Manganese-dioxide primary cells / batteries
Chapter 85, Manganese-dioxide primary cells / batteries. China VAT rebate 13%.
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HS 850650 Lithium primary cells / batteries
Chapter 85, Lithium primary cells / batteries. China VAT rebate 13%.
Glossary
HS Code, Harmonized System Code
A six-digit international product classification code used by customs authorities worldwide to identify goods, assess duties, and apply trade controls. Countries extend the six-digit base with additional digits for tariff and statistical purposes (10-digit HTS in the US, 8-digit CN code in the EU, 10-digit AHECC in Australia).
Free download
Free PDF: thirty-point factory audit checklist used on every chemical-park site visit, mapped against the HS-code-leading Chinese producers.