Product classification
HS code for Distribution transformer: 8504.21
Electrical transformers, liquid dielectric, having a power handling capacity not exceeding 650kVA.
Classification of distribution transformer under HS 8504.21
Distribution transformers are classified under HS code 8504.21 because they are electrical transformers utilizing a liquid dielectric (typically oil) for cooling and insulation, with a power handling capacity not exceeding 650 kVA. This classification is determined by General Interpretative Rules (GIR) 1 and 6, following the specific subheadings for liquid dielectric transformers. These units are essential for stepping down voltage from primary distribution lines to levels suitable for residential or commercial use. The classification depends strictly on the cooling medium and the kVA rating. The liquid dielectric serves two purposes: providing electrical insulation between internal components and dissipating heat generated during operation. Under the Harmonized System, heading 8504 covers electrical transformers, static converters, and inductors, and the subheadings are divided based on whether the transformer uses a liquid dielectric or another medium like air or cast resin.
- Covers
- Pole-mounted distribution transformers
- Pad-mounted liquid-filled transformers
- Single-phase liquid dielectric transformers
- Three-phase liquid dielectric transformers under 650 kVA
- Also under 8504.21
- ABB distribution transformers
- Siemens liquid-filled transformers
- GE Prolec distribution transformers
- Eaton Cooper Power Systems transformers
- Schneider Electric oil-immersed transformers
Codes often confused with 8504.21
Common mistake. These are often confused with HS code 8504.31, which covers dry-type transformers (non-liquid dielectric). They are also frequently misclassified under 8504.22 if the power handling capacity exceeds 650 kVA but is below 10,000 kVA. It is critical to verify the kVA rating and the cooling medium before assigning the code.
Top exporters and importers of HS 850421 (the code used for distribution transformer), 2025
In 2025, the largest exporter of HS 850421 (the code used for distribution transformer) in UN Comtrade data was China, with 16% of world exports; the largest importer in UN Comtrade data was the United States, with 36% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Figures cover everything classified under HS 850421, not only distribution transformer.
Top exporters 2025 · share of world exports
- 1 China $570M 16% of world exports
- 2 Mexico $466M 13% of world exports
- 3 South Korea $349M 9.6% of world exports
World total: $3.6B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $1.4B 36% of world imports
- 2 Germany $281M 7.2% of world imports
- 3 France $150M 3.8% of world imports
World total: $3.9B Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM code for distribution transformer
Brazil classifies distribution transformer under NCM 8504.21.00: HS 8504.21 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about distribution transformer
What is the HS code for Distribution transformer?
The HS code for Distribution transformer is 850421 (Electrical transformers; liquid dielectric, having a power handling capacity not exceeding 650kVA). The HS code for a liquid dielectric distribution transformer with a capacity not exceeding 650 kVA is 8504.21.
How do I classify Distribution transformer for customs?
Distribution transformer is classified under HS code 850421 — Electrical transformers; liquid dielectric, having a power handling capacity not exceeding 650kVA. This is a 6-digit subheading level code.
Does the type of oil used affect the HS code?
No, as long as the transformer uses a liquid dielectric (mineral oil, silicone, or vegetable oil), it remains under the liquid dielectric subheadings of 8504.
Which countries are the top exporters of distribution transformer (HS 850421)?
In 2025, the top exporters of HS 850421 (the code used for distribution transformer) in UN Comtrade data were China ($570M, 16% of world exports), Mexico ($466M) and South Korea ($349M). World exports came to about $3.6B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of distribution transformer (HS 850421)?
In 2025, the top importers of HS 850421 (the code used for distribution transformer) in UN Comtrade data were the United States ($1.4B, 36% of world imports), Germany ($281M) and France ($150M). World imports came to about $3.9B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Is the HS code for Distribution transformer the same in all countries?
The base HS code 850421 for Distribution transformer is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for distribution transformer in Brazil?
In Brazil, distribution transformer (HS 850421) is classified under NCM 8504.21.00.