HS code · 6-digit subheading
HS Code 8504.31 – Electrical transformers; n.e.c. in item no. 8504.2, having a power handling capacity not exceeding 1kVA
HS code 8504.31 is the 6-digit subheading for electrical transformers, n.e.c. in item no. 8504.2, having a power handling capacity not exceeding 1kVA. It is used for control transformers, isolation transformers, audio transformers, power supply transformers and PCB mount transformers.
What HS 8504.31 covers
This HS code covers small, general-purpose electrical transformers that do not use liquid dielectric insulation and have a power handling capacity of up to 1kVA. These "dry-type" transformers are ubiquitous in electronics, consumer appliances, control systems, and low-power industrial applications where safety, size, and cost are critical. They are often used to step down voltage for electronic circuits or provide isolation. International trade in these transformers is vast and global, driven by the manufacturing of a wide array of electronic and electrical goods. Major importers include countries with large electronics assembly industries, such as China, Mexico, and Vietnam, as well as industrialized nations for repair and replacement markets like the USA and Germany. Exporters are typically countries with strong electronics manufacturing bases, including China, Taiwan, and various European countries. Buyers prioritize compact size, efficiency, safety certifications, and cost-effectiveness.
- Covers
- Control transformers
- Isolation transformers
- Audio transformers
- Power supply transformers
- PCB mount transformers
- Bell transformers
- Medical isolation transformers
- Examples
- Hammond Manufacturing control transformers
- Triad Magnetics audio transformers
- Talema toroidal transformers
- Murata power transformers
- Pulse Electronics signal transformers
Codes often confused with 8504.31
Common mistake. These can be confused with power supplies (8504.40) if they integrate rectification or other functions, or with slightly larger dry-type transformers (8504.32) if the kVA limit is not strictly observed. The "dry-type" and "not exceeding 1kVA" are key.
Top exporters and importers of HS code 850431, 2025
In 2025, the largest exporter of HS code 850431 in UN Comtrade data was China, with 32% of world exports; the largest importer in UN Comtrade data was the United States, with 11% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Top exporters 2025 · share of world exports
- 1 China $1.9B 32% of world exports
- 2 Hong Kong $613M 10% of world exports
- 3 Germany $525M 8.7% of world exports
World total: $6.1B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $689M 11% of world imports
- 2 Germany $462M 7.4% of world imports
- 3 Hong Kong $383M 6.2% of world imports
World total: $6.2B 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 codes for 8504.31 6
Brazil splits HS 8504.31 into 6 NCM codes, Mercosur's 8-digit tariff lines.
- 8504.31.1 For frequencies of 60 Hz or lessPara frequências inferiores ou iguais a 60 Hz Group
- 8504.31.11 Current transformers, up to 1 kVA, 60 Hz or lessTransformadores de corrente
- 8504.31.19 Other transformers up to 1 kVA, 60 Hz or lessOutros
- 8504.31.9 OtherOutros Group
- 8504.31.91 Flyback transformers, over 18 kV, 32 kHz or moreTransformador de saída horizontal (fly back), com tensão de saída superior a 18 kV e frequência de varredura horizontal igual ou superior a 32 kHz
- 8504.31.92 IF/detection/ratio/linearity/focus transformersTransformadores de FI, de detecção, de relação, de linearidade ou de foco
- 8504.31.93 PTH or SMD transformers, up to 50 x 50 x 25 mmOutros, de largura e comprimento não superior a 50 mm e altura não superior a 25 mm, próprios para montagem por inserção (PTH - Pin Through Hole) ou montagem em superfície (SMD - Surface Mounted Device)
- 8504.31.99 Other transformers up to 1 kVA, over 60 HzOutros
All Brazil NCM codes in heading 85.04 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 8504.31
What is HS code 850431?
HS code 850431 is a 6-digit subheading in the Harmonized System that covers: Electrical transformers; n.e.c. in item no. 8504.2, having a power handling capacity not exceeding 1kVA. This HS code covers small, general-purpose electrical transformers that do not use liquid dielectric insulation and have a power handling capacity of up to 1kVA. These "dry-type" transformers are ubiquitous in electronics, consumer appliances, control systems, and low-power industrial applications where safety, size, and cost are critical. They are often used to step down voltage for electronic circuits or provide isolation. International trade in these transformers is vast and global, driven by the manufacturing of a wide array of electronic and electrical goods. Major importers include countries with large electronics assembly industries, such as China, Mexico, and Vietnam, as well as industrialized nations for repair and replacement markets like the USA and Germany. Exporters are typically countries with strong electronics manufacturing bases, including China, Taiwan, and various European countries. Buyers prioritize compact size, efficiency, safety certifications, and cost-effectiveness.
What products fall under HS code 850431?
Control transformers, Isolation transformers, Audio transformers, Power supply transformers, PCB mount transformers, Bell transformers, Medical isolation transformers
What are common misclassifications for HS code 850431?
These can be confused with power supplies (8504.40) if they integrate rectification or other functions, or with slightly larger dry-type transformers (8504.32) if the kVA limit is not strictly observed. The "dry-type" and "not exceeding 1kVA" are key.
Which countries are the top exporters of goods under HS code 850431?
In 2025, the top exporters of HS code 850431 in UN Comtrade data were China ($1.9B, 32% of world exports), Hong Kong ($613M) and Germany ($525M). World exports came to about $6.1B, 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 goods under HS code 850431?
In 2025, the top importers of HS code 850431 in UN Comtrade data were the United States ($689M, 11% of world imports), Germany ($462M) and Hong Kong ($383M). World imports came to about $6.2B, 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.
How is HS code 850431 structured?
HS code 850431 is a 6-digit subheading under the Harmonized System. The first 2 digits (85) identify the chapter, digits 3-4 (04) identify the heading, and digits 5-6 (31) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 850431?
Brazil splits HS code 850431 into 6 NCM codes: 8504.31.11 (Current transformers, up to 1 kVA, 60 Hz or less), 8504.31.19 (Other transformers up to 1 kVA, 60 Hz or less), 8504.31.91 (Flyback transformers, over 18 kV, 32 kHz or more), 8504.31.92 (IF/detection/ratio/linearity/focus transformers), 8504.31.93 (PTH or SMD transformers, up to 50 x 50 x 25 mm), 8504.31.99 (Other transformers up to 1 kVA, over 60 Hz). The first 6 digits of each match the HS code.