Product classification
HS code for Watch battery: 8506.40
Cells and batteries, primary, silver oxide.
Classification of watch battery under HS 8506.40
Watch batteries are classified under HS code 8506.40 because they are defined as primary cells and primary batteries utilizing silver oxide as the active cathode material. In the Harmonized System, batteries are categorized primarily by their chemical composition and whether they are rechargeable (secondary) or non-rechargeable (primary). Silver oxide batteries are the industry standard for quartz watches due to their high energy-to-weight ratio and their ability to maintain a stable voltage discharge until the end of their life cycle. According to General Interpretative Rule (GIR) 1, classification is determined by the terms of the headings and any relative section or chapter notes. Chapter 85, Note 3, clarifies the distinction between primary cells and accumulators. Since watch batteries of this type are designed for single use and rely on the silver oxide-zinc chemical reaction, they are specifically assigned to the 8506.40 subheading. The classification remains consistent regardless of the battery's physical size, provided the chemistry is silver oxide.
- Covers
- Silver oxide button cells
- SR44 and SR44W batteries
- SR626SW watch batteries
- Low-drain silver oxide cells for analog watches
- High-drain silver oxide cells for digital or chronograph watches
- Multi-drain silver oxide cells
- Also under 8506.40
- Renata 377
- Sony SR626SW
- Maxell SR44
- Energizer 357/303
- Varta V371
Codes often confused with 8506.40
Common mistake. Watch batteries are frequently misclassified under HS code 8506.50, which covers lithium primary cells. While many modern watches use lithium coin cells (like the CR2032), these must be declared under 8506.50 due to their different chemical composition. Another common error is using HS code 8507.80, which is reserved for rechargeable (secondary) batteries. If a watch uses a rechargeable lithium-ion cell, it cannot be classified under 8506.40.
Top exporters and importers of HS 850640 (the code used for watch battery), 2025
In 2025, the largest exporter of HS 850640 (the code used for watch battery) in UN Comtrade data was Japan, with 43% of world exports; the largest importer in UN Comtrade data was the United States, with 24% 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 850640, not only watch battery.
Top exporters 2025 · share of world exports
- 1 Japan $134M 43% of world exports
- 2 Switzerland $57M 18% of world exports
- 3 Singapore $31M 9.9% of world exports
World total: $314M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $75M 24% of world imports
- 2 Hong Kong $45M 14% of world imports
- 3 Ireland $32M 10% of world imports
World total: $310M 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 watch battery
Brazil splits HS 8506.40 into 2 NCM codes. Pick the one that matches your product:
- 8506.40.10Silver oxide cells and batteries, up to 300 cm³
- 8506.40.90Silver oxide cells and batteries, over 300 cm³
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about watch battery
What is the HS code for Watch battery?
The HS code for Watch battery is 850640 (Cells and batteries; primary, silver oxide). The HS code for a standard silver oxide watch battery is 8506.40.
How do I classify Watch battery for customs?
Watch battery is classified under HS code 850640 — Cells and batteries; primary, silver oxide. This is a 6-digit subheading level code.
Can alkaline button cells be classified here?
No, alkaline button cells (often used in cheaper watches or toys) are classified under HS code 8506.10, as they utilize manganese dioxide.
Which countries are the top exporters of watch battery (HS 850640)?
In 2025, the top exporters of HS 850640 (the code used for watch battery) in UN Comtrade data were Japan ($134M, 43% of world exports), Switzerland ($57M) and Singapore ($31M). World exports came to about $314M, 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 watch battery (HS 850640)?
In 2025, the top importers of HS 850640 (the code used for watch battery) in UN Comtrade data were the United States ($75M, 24% of world imports), Hong Kong ($45M) and Ireland ($32M). World imports came to about $310M, 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 Watch battery the same in all countries?
The base HS code 850640 for Watch battery 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 watch battery in Brazil?
Brazil splits HS 850640 into 2 NCM codes, so the right one for watch battery depends on the product's details: 8506.40.10 (Silver oxide cells and batteries, up to 300 cm³), 8506.40.90 (Silver oxide cells and batteries, over 300 cm³).