Chapter 85 is the major category in the HS classification system covering 'Electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles'. This chapter covers a wide range of products from household appliances to industrial power equipment, with the core characteristic being the production, conversion, storage, or utilization of electrical energy. Transformers, as key equipment for power conversion, are naturally classified in this chapter. Heading 8504 covers 'Electrical transformers, static converters (for example, rectifiers) and inductors'. This heading includes power transformers, electronic transformers, ballasts, inverters, rectifiers, inductors, etc. Note, however, that 8504 only includes static converters, not rotary converters (such as motor-generator sets, classified under 8502). Transformers are further subdivided by capacity, use, etc. Code 850433 is a 6-digit subheading. The first 2 digits '85' represent Chapter 85 (Electrical machinery and equipment). Digits 3-4 '04' represent heading 8504 (Electrical transformers, static converters and inductors). Digits 5-6 '33' represent subheading 850433, specifically 'Transformers, having a power handling capacity exceeding 16 kVA but not exceeding 500 kVA'. There may be further 8-digit or 10-digit codes under this subheading, but 6 digits is the internationally harmonized level. Note that the capacity range is the core distinguishing point. The goods are transformers with a capacity between 16-500 kVA, therefore classified under 850433. If the capacity is ≤16 kVA, it should be classified under 850431; if the capacity is >500 kVA but ≤10 MVA, classified under 850434; if >10 MVA, classified under 850435. If it is an electronic transformer (such as a small transformer used in electronic equipment), even if the capacity falls within this range, it may be classified under other subheadings based on use, but generally still classified by capacity.
Chapter
Chapter 85 is the major category in the HS classification system covering 'Electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles'. This chapter covers a wide range of products from household appliances to industrial power equipment, with the core characteristic being the production, conversion, storage, or utilization of electrical energy. Transformers, as key equipment for power conversion, are naturally classified in this chapter.
Heading
Heading 8504 covers 'Electrical transformers, static converters (for example, rectifiers) and inductors'. This heading includes power transformers, electronic transformers, ballasts, inverters, rectifiers, inductors, etc. Note, however, that 8504 only includes static converters, not rotary converters (such as motor-generator sets, classified under 8502). Transformers are further subdivided by capacity, use, etc.
Digit Breakdown
Code 850433 is a 6-digit subheading. The first 2 digits '85' represent Chapter 85 (Electrical machinery and equipment). Digits 3-4 '04' represent heading 8504 (Electrical transformers, static converters and inductors). Digits 5-6 '33' represent subheading 850433, specifically 'Transformers, having a power handling capacity exceeding 16 kVA but not exceeding 500 kVA'. There may be further 8-digit or 10-digit codes under this subheading, but 6 digits is the internationally harmonized level. Note that the capacity range is the core distinguishing point.
Classification Basis
The goods are transformers with a capacity between 16-500 kVA, therefore classified under 850433. If the capacity is ≤16 kVA, it should be classified under 850431; if the capacity is >500 kVA but ≤10 MVA, classified under 850434; if >10 MVA, classified under 850435. If it is an electronic transformer (such as a small transformer used in electronic equipment), even if the capacity falls within this range, it may be classified under other subheadings based on use, but generally still classified by capacity.
📝 Declaration Elements
Product Name: The specific name of the declared goods, such as 'power transformer', 'dry-type transformer', etc., which should accurately reflect the product attributes. Use: Explain the application scenario of the transformer, such as 'used for power transmission and distribution', 'used for industrial equipment', etc. Brand: Fill in the manufacturer or brand name; if there is no brand, fill in 'no brand'. Model: Fill in the specific model of the product for identifying specifications. Capacity: Rated capacity, in kilovolt-amperes (kVA), must be accurately filled in. Type: Such as 'dry-type', 'oil-immersed', etc., which affects classification and regulatory conditions. Phase: Such as 'single-phase', 'three-phase', which is a basic parameter of the transformer. Product Name: Three-phase dry-type power transformer; Use: Used for factory power distribution system; Brand: ABB; Model: SCB10-1000/10; Capacity: 1000 kVA; Type: Dry-type; Phase: Three-phase. Capacity unit mistakenly filled in as kW or W, resulting in subheading classification errors. Transformer type not distinguished (dry-type/oil-immersed), which may affect regulatory conditions. Electronic transformers (such as those used for power adapters) mistakenly classified under this code, when they may actually be classified under 850431 or others.
Product Name
The specific name of the declared goods, such as 'power transformer', 'dry-type transformer', etc., which should accurately reflect the product attributes.
⚠️ Writing only 'transformer' without distinguishing the type, resulting in ambiguous classification.
Use
Explain the application scenario of the transformer, such as 'used for power transmission and distribution', 'used for industrial equipment', etc.
⚠️ Filling in 'used for voltage transformation', which is too general and has no practical significance.
Brand
Fill in the manufacturer or brand name; if there is no brand, fill in 'no brand'.
⚠️ Mistakenly filling in the trader's name as the brand.
Model
Fill in the specific model of the product for identifying specifications.
⚠️ Model filled in incompletely or inconsistent with the actual product.
Capacity
Rated capacity, in kilovolt-amperes (kVA), must be accurately filled in.
⚠️ Unit mistakenly filled in as watts (W) or kilowatts (kW), resulting in classification errors.
Type
Such as 'dry-type', 'oil-immersed', etc., which affects classification and regulatory conditions.
⚠️ Type not filled in, which may affect customs review.
Phase
Such as 'single-phase', 'three-phase', which is a basic parameter of the transformer.
⚠️ Omitted or incorrectly filled in, resulting in inconsistency with the actual product.
Example： Product Name: Three-phase dry-type power transformer; Use: Used for factory power distribution system; Brand: ABB; Model: SCB10-1000/10; Capacity: 1000 kVA; Type: Dry-type; Phase: Three-phase.
Common Mistakes：
Capacity unit mistakenly filled in as kW or W, resulting in subheading classification errors.
Transformer type not distinguished (dry-type/oil-immersed), which may affect regulatory conditions.
Electronic transformers (such as those used for power adapters) mistakenly classified under this code, when they may actually be classified under 850431 or others.
🎯 Classification Logic
The core basis for classification is the rated capacity of the transformer, in kilovolt-amperes (kVA). According to HS rules, subheadings 850431 to 850435 are divided by increasing capacity. 850433 specifically refers to transformers with a capacity exceeding 16 kVA but not exceeding 500 kVA. When classifying, it is necessary to confirm whether the capacity falls within this range and to exclude other types (such as electronic transformers, instrument transformers, etc.). In addition, it is necessary to note whether it is a static converter or a transformer, as they are different subheadings under 8504. 850431 Transformers, capacity ≤16 kVA: Transformers with a capacity not exceeding 16 kVA are classified under this code; if exceeded, classified under 850433. 850434 Transformers, capacity >500 kVA and ≤10 MVA: Transformers with a capacity exceeding 500 kVA but not exceeding 10 MVA are classified under this code, which does not overlap with the capacity range of 850433. 850440 Static converters: Static converters (such as rectifiers, inverters) are classified under 850440, while transformers are classified under 850431-850435. 850450 Inductors: Inductors (such as chokes) are classified under 850450, which have a different function from transformers. 850432 Transformers, 16 kVA < capacity ≤ 500 kVA (other): Note: 850432 may be used in certain countries for specific types of transformers, but in the international HS, 850432 is empty or used for other purposes; confirmation is needed. Generally, 850433 is for 16-500 kVA. Confirm whether the capacity unit is kVA and whether it is between 16-500 kVA. Confirm whether it is a transformer rather than a converter or inductor. Confirm whether it is static rather than rotary. Confirm whether it is a power transformer rather than an electronic transformer. Confirm whether it has other functions (such as voltage stabilization), which may affect classification.
Basis
The core basis for classification is the rated capacity of the transformer, in kilovolt-amperes (kVA). According to HS rules, subheadings 850431 to 850435 are divided by increasing capacity. 850433 specifically refers to transformers with a capacity exceeding 16 kVA but not exceeding 500 kVA. When classifying, it is necessary to confirm whether the capacity falls within this range and to exclude other types (such as electronic transformers, instrument transformers, etc.). In addition, it is necessary to note whether it is a static converter or a transformer, as they are different subheadings under 8504.
Confused Codes：
850431 - Transformers, capacity ≤16 kVA
Transformers with a capacity not exceeding 16 kVA are classified under this code; if exceeded, classified under 850433.
850434 - Transformers, capacity >500 kVA and ≤10 MVA
Transformers with a capacity exceeding 500 kVA but not exceeding 10 MVA are classified under this code, which does not overlap with the capacity range of 850433.
850440 - Static converters
Static converters (such as rectifiers, inverters) are classified under 850440, while transformers are classified under 850431-850435.
850450 - Inductors
Inductors (such as chokes) are classified under 850450, which have a different function from transformers.
850432 - Transformers, 16 kVA < capacity ≤ 500 kVA (other)
Note: 850432 may be used in certain countries for specific types of transformers, but in the international HS, 850432 is empty or used for other purposes; confirmation is needed. Generally, 850433 is for 16-500 kVA.
Self-Check：
✓ Confirm whether the capacity unit is kVA and whether it is between 16-500 kVA.
✓ Confirm whether it is a transformer rather than a converter or inductor.
✓ Confirm whether it is static rather than rotary.
✓ Confirm whether it is a power transformer rather than an electronic transformer.
✓ Confirm whether it has other functions (such as voltage stabilization), which may affect classification.
❓ FAQ
How to look up the HS code for transformers? First determine the rated capacity of the transformer (kVA), then select the subheading based on the capacity range: ≤16 kVA is 850431, 16-500 kVA is 850433, >500 kVA and ≤10 MVA is 850434, >10 MVA is 850435. At the same time, confirm whether it is a static transformer and refer to customs tariff and classification decisions. Which code should a transformer with a capacity of 16 kVA be classified under? According to HS rules, 850431 is for capacity not exceeding 16 kVA, and 850433 is for exceeding 16 kVA but not exceeding 500 kVA. Therefore, a capacity of exactly 16 kVA should be classified under 850431, because 'not exceeding' includes the number itself. If it is 16.1 kVA, it is classified under 850433. Should an electronic transformer (such as for switching power supplies) with a capacity between 16-500 kVA be classified under 850433? Not necessarily. Electronic transformers usually have lower power; if the capacity falls within this range, they may still be classified by capacity under 850433. However, if it is a high-frequency switching transformer, it may be classified under 850431 or others, depending on specific functions, uses, and customs classification decisions. It is recommended to provide technical parameters and consult customs. How are transformers and static converters distinguished in HS codes? Transformers (850431-850435) are used to change AC voltage based on the principle of electromagnetic induction. Static converters (850440) are used to change the type or frequency of current, such as rectifiers and inverters. They are different subheadings under 8504, and classification should be determined based on function. What are the consequences of filling in the wrong capacity unit when declaring transformers? Filling in the wrong capacity unit may lead to subheading classification errors, thereby affecting tariffs, regulatory conditions, and statistics. For example, mistakenly filling in kVA as kW may cause the capacity value to fall into a different range, resulting in classification errors. Customs may require amendment or impose penalties. What regulatory documents are required for importing transformers classified under 850433? Regulatory documents depend on the specific country's/region's regulations. Generally, transformers may involve import licenses for mechanical and electrical products, energy efficiency labels, etc. It is recommended to check the regulatory conditions published by the General Administration of Customs and the latest tariff, or consult a professional customs broker. Is there a difference in classification between dry-type transformers and oil-immersed transformers? In terms of HS codes, both are classified by capacity under 850431-850435, with no difference. However, regulatory conditions may differ, such as oil-immersed transformers possibly involving environmental requirements. When declaring, the type must be truthfully filled in for customs supervision. If a transformer has a capacity of 500 kVA, should it be classified under 850433 or 850434? 850433 is for exceeding 16 kVA but not exceeding 500 kVA, including 500 kVA; 850434 is for exceeding 500 kVA. Therefore, a capacity of 500 kVA should be classified under 850433. If it is 500.1 kVA, it is classified under 850434.
Q: How to look up the HS code for transformers?
A: First determine the rated capacity of the transformer (kVA), then select the subheading based on the capacity range: ≤16 kVA is 850431, 16-500 kVA is 850433, >500 kVA and ≤10 MVA is 850434, >10 MVA is 850435. At the same time, confirm whether it is a static transformer and refer to customs tariff and classification decisions.
Q: Which code should a transformer with a capacity of 16 kVA be classified under?
A: According to HS rules, 850431 is for capacity not exceeding 16 kVA, and 850433 is for exceeding 16 kVA but not exceeding 500 kVA. Therefore, a capacity of exactly 16 kVA should be classified under 850431, because 'not exceeding' includes the number itself. If it is 16.1 kVA, it is classified under 850433.
Q: Should an electronic transformer (such as for switching power supplies) with a capacity between 16-500 kVA be classified under 850433?
A: Not necessarily. Electronic transformers usually have lower power; if the capacity falls within this range, they may still be classified by capacity under 850433. However, if it is a high-frequency switching transformer, it may be classified under 850431 or others, depending on specific functions, uses, and customs classification decisions. It is recommended to provide technical parameters and consult customs.
Q: How are transformers and static converters distinguished in HS codes?
A: Transformers (850431-850435) are used to change AC voltage based on the principle of electromagnetic induction. Static converters (850440) are used to change the type or frequency of current, such as rectifiers and inverters. They are different subheadings under 8504, and classification should be determined based on function.
Q: What are the consequences of filling in the wrong capacity unit when declaring transformers?
A: Filling in the wrong capacity unit may lead to subheading classification errors, thereby affecting tariffs, regulatory conditions, and statistics. For example, mistakenly filling in kVA as kW may cause the capacity value to fall into a different range, resulting in classification errors. Customs may require amendment or impose penalties.
Q: What regulatory documents are required for importing transformers classified under 850433?
A: Regulatory documents depend on the specific country's/region's regulations. Generally, transformers may involve import licenses for mechanical and electrical products, energy efficiency labels, etc. It is recommended to check the regulatory conditions published by the General Administration of Customs and the latest tariff, or consult a professional customs broker.
Q: Is there a difference in classification between dry-type transformers and oil-immersed transformers?
A: In terms of HS codes, both are classified by capacity under 850431-850435, with no difference. However, regulatory conditions may differ, such as oil-immersed transformers possibly involving environmental requirements. When declaring, the type must be truthfully filled in for customs supervision.
Q: If a transformer has a capacity of 500 kVA, should it be classified under 850433 or 850434?
A: 850433 is for exceeding 16 kVA but not exceeding 500 kVA, including 500 kVA; 850434 is for exceeding 500 kVA. Therefore, a capacity of 500 kVA should be classified under 850433. If it is 500.1 kVA, it is classified under 850434.
⚠️ Disclaimer: HS code classification, declaration elements, tariff rates and regulatory conditions on this page are for reference only and do not constitute legal advice on customs classification. Tariff rates and regulations are subject to change; the latest announcements from the General Administration of Customs and on-site determinations shall prevail. Please consult professional customs brokers or customs authorities before import/export.