What is SKU?
Stock Keeping Unit — the seller-defined identifier for a product you sell.
A SKU (Stock Keeping Unit) is the seller-defined identifier you assign to each distinct product or variation you sell. On Amazon, the SKU (sometimes called the seller SKU or MSKU) is the label you control, in contrast to the ASIN that Amazon controls. Whenever you create an offer, you either supply your own SKU or let Amazon auto-generate one, and that code becomes the key your account, your reports, and your accounting system all use to refer to that exact item.
The SKU is the grain at which real businesses run their numbers. Inventory counts, reorder points, and cost of goods sold are all tracked per SKU, because the SKU is the only identifier that maps cleanly to a single product at a single cost in your own records. Get your SKU scheme right and reconciliation, valuation, and reimbursement all get easier; get it wrong and every downstream report inherits the mess.
What is a Stock Keeping Unit, and how is it different from an ASIN?
A stock keeping unit is an internal code a seller uses to identify and count a specific product. You decide what it looks like. Amazon never shows your SKU to shoppers; it's purely for your operations. The ASIN, by contrast, is Amazon's public product ID shared by every seller of that product. The same ASIN can be sold under thousands of different sellers' SKUs.
This split is why a clean SKU scheme pays off. Because you define the SKU, you can encode useful information into it: brand, product line, variation, supplier, or batch. A common pattern is something readable like BRAND-PRODUCT-SIZE-COLOR. The goal is a code that is unique, stable, and human-legible, so that when a SKU shows up in a settlement report or a reimbursement case, you instantly know which product and which cost it refers to.
- •You assign and control the SKU; Amazon assigns the ASIN
- •The SKU is private to your account and never shown to shoppers
- •One ASIN can be sold under many sellers' SKUs
- •Good SKUs are unique, stable, and human-readable
- •Encode brand, variation, and supplier to speed reconciliation
How to find a SKU number on Amazon
To do an Amazon SKU lookup, go to Seller Central and open Manage Inventory; the SKU column sits next to each listing alongside its ASIN and FNSKU. You can also search inventory by SKU directly, export the full list to a flat file, or pull SKUs through the Amazon API. Your settlement reports and FBA inventory reports are likewise keyed by SKU, which is what makes the SKU the natural join key when you reconcile payouts to products.
If you sell across channels, note that platforms use the term the same way: a Shopify stock keeping unit, an Etsy SKU, and an Amazon SKU all serve the same role on their respective storefronts. Sellers running multichannel operations usually maintain a master SKU and map each marketplace's SKU back to it, so that a single product's cost and inventory aren't fragmented across systems. Keeping those mappings tight is what prevents overselling and double-counted inventory.
Why your SKU scheme drives clean COGS and inventory value
Cost of goods sold and inventory valuation are calculated per SKU. When you receive stock, the landed cost attaches to the SKU; when a unit sells, that SKU's cost flows into COGS. If two different products share a SKU, or if you reuse an old SKU for a new product with a different cost, your cost layers blend and your margins become unreliable. A disciplined one-product-one-SKU rule keeps valuation honest.
The same logic powers reimbursement accuracy. Amazon reports lost and damaged units by SKU and FNSKU, so the SKU is how you connect a warehouse loss back to the actual unit cost you paid. BeanHawk uses the SKU as the anchor to match settlement lines, inventory movements, and recovered reimbursements to the right product, so your books reflect true per-product profit rather than a marketplace-level blur.
Frequently asked questions
- What is a SKU number on Amazon?
- A SKU (Stock Keeping Unit) number on Amazon is the seller-defined identifier you assign to each product you list. It is private to your account, used to track inventory and costs, and distinct from the ASIN, which is Amazon's public product ID.
- How do I find my SKU number on Amazon?
- Open Seller Central, go to Manage Inventory, and the SKU appears next to each listing alongside the ASIN and FNSKU. You can also search by SKU, export the inventory file, or retrieve SKUs through the Amazon API and your settlement reports.
- What does SKU mean on Etsy or Shopify?
- SKU means the same thing on every platform: a Stock Keeping Unit is the seller's own identifier for a product or variation. An Etsy SKU or a Shopify stock keeping unit plays the identical role to an Amazon SKU on those storefronts, which is why multichannel sellers map them back to one master SKU.
- What makes a good SKU scheme?
- A good SKU is unique, stable, and human-readable, typically encoding brand, product line, and variation in a consistent pattern. Avoid reusing retired SKUs for new products, because shared SKUs blend cost layers and corrupt your COGS and inventory value.
- What is the difference between a SKU and an FNSKU?
- A SKU is the identifier you assign to an offer in your own records. An FNSKU is the barcode Amazon generates from that SKU and prints on the physical unit so its warehouses can track your inventory. One SKU produces one FNSKU per condition when enrolled in FBA.
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