A unique alphanumeric identifier assigned to each distinct product or variant for inventory tracking and management. Different sizes or colors of the same product each get their own SKU.
Understanding SKU (Stock Keeping Unit)
A Stock Keeping Unit (SKU) is a unique alphanumeric code assigned to each distinct product variant in a seller's inventory. SKUs enable precise tracking of inventory quantities, sales velocity, and profitability at the individual product level across all sales channels.
Unlike UPCs or ASINs (which are standardized across all sellers), SKUs are created by the individual seller and can follow any naming convention. A good SKU system encodes useful information — for example, "BLU-CASE-IPH15-PRO" immediately tells you the color, product type, and phone model.
Each variation of a product — different size, color, material, or bundle configuration — should have its own unique SKU. This granularity is essential for accurate inventory management, purchasing decisions, and profitability analysis. Without proper SKUs, you cannot determine which specific products are winners and which are losers.
Why It Matters for Ecommerce
For multi-channel ecommerce sellers, a consistent SKU system across Amazon, Shopify, eBay, and Walmart is the key to unified inventory tracking and accurate accounting. When all platforms use the same SKU codes, you can merge reports from multiple channels and analyze total sales, fees, and profitability per product.
Practical Example
You sell a phone case in 3 colors and 2 sizes = 6 SKUs: "CASE-BLK-SM," "CASE-BLK-LG," "CASE-BLU-SM," "CASE-BLU-LG," "CASE-RED-SM," "CASE-RED-LG." When you list on Amazon and Shopify, use these same SKUs on both platforms. Now your analytics dashboard can show total units sold for "CASE-BLU-LG" across all channels.
Related Terms
FBA (Fulfillment by Amazon)
A service where sellers send inventory to Amazon's warehouses and Amazon handles storage, packing, shipping, and customer service. Sellers pay storage and fulfillment fees in exchange.
EcommerceMulti-Channel Selling
The practice of listing and selling products on multiple platforms simultaneously (e.g., Amazon, Shopify, eBay, Walmart). Requires careful inventory sync and consolidated bookkeeping.
EcommerceGross Merchandise Value (GMV)
The total value of all goods sold through a marketplace or storefront over a period, before deducting fees, refunds, taxes, and discounts. A top-line metric for measuring sales volume.
Put This Knowledge Into Practice
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