HS Code for Transformers

Electrical transformers point toward heading 8504 of the HTSUS, which covers electrical transformers, static converters and inductors. The main branching factor for a finished transformer is its power handling capacity: small transformers not exceeding 1 kVA point toward 8504.31, then the capacity bands step up through 8504.32 (over 1 to 16 kVA), 8504.33 (over 16 to 500 kVA) and 8504.34 (over 500 kVA). Parts of transformers point toward subheading 8504.90. General rates vary with capacity, from Free up to around 6.6% on some small rated transformers, with the mid and large bands around 1.6% to 2.4%. Identifying the power handling capacity, and whether the item is a complete transformer or a part, is the first step in exploring the most appropriate subheading.

Electrical transformers point toward heading 8504 of the HTSUS (electrical transformers, static converters and inductors). The heading is the natural starting point, and the first branch is whether the item is a complete transformer or a part.

For a complete transformer, the primary branching factor is the power handling capacity, measured in volt-amperes (VA) or kilovolt-amperes (kVA). Transformers with a power handling capacity not exceeding 1 kVA point toward subheading 8504.31, which further separates unrated units from rated ones and splits the rated units around the 40 VA threshold. From there the capacity bands step up: over 1 kVA but not over 16 kVA points toward 8504.32; over 16 kVA but not over 500 kVA points toward 8504.33; and over 500 kVA points toward 8504.34. Confirming the rated capacity is therefore the key first step.

Parts of transformers point toward subheading 8504.90. Printed circuit assemblies point toward 8504.90.20, other parts toward 8504.90.41, parts of telecommunication converters or inductors toward 8504.90.65, other converter and inductor parts toward 8504.90.75, and parts identifiable specifically for transformers toward the 8504.90.96 line. Distinguishing a complete transformer from a core, winding or other part is the second key judgment.

A practical way to approach it is to confirm the item is a transformer (not a static converter or power supply, which sit on the 8504.40 lines of the same heading), then read its power handling capacity to select the capacity band, or route it to 8504.90 if it is a part. That sequence usually points toward a single most-appropriate subheading to explore. It is worth avoiding two traps: treating a power supply or rectifier as a transformer, and defaulting a small rated transformer to a low band without checking the 40 VA breakout, which can change the rate.

General duty rates for transformers vary with their power handling capacity. Some small transformers enter Free (for example unrated units not exceeding 1 kVA) while small rated transformers with a capacity less than 40 VA carry the highest general rate in this set, around 6.6%. Rated transformers from 40 VA to 1 kVA are around 1.6%, the over-1-to-16 kVA band around 2.4%, and the larger bands (over 16 to 500 kVA and over 500 kVA) around 1.6%. Parts of transformers under subheading 8504.90 are generally Free. So the power handling capacity (and, for small units, the 40 VA threshold) can move the estimated duty noticeably, which makes confirming the rating worthwhile. Preferential rates under free trade agreements may reduce or eliminate these duties for qualifying origins. These figures are estimates for general planning purposes only.