SKU is an acronym for "stock-keeping unit". SKUs are commonly used by stores to keep inventory and speed up the purchasing process. An SKU can be used to order an item from a warehouse, look up a price or to find out how many items a store has in stock. In many department stores and big-box warehouses, the UPC (universal product code) is used as an SKU. SKUs frequently are made up of numbers and bar codes that identify an item to the machines designed to read the bar code.

Look for a bar code on the item in question. The bar code will be a series of black vertical lines of equal length, placed together in a tight group. Look for a tag or sticker with the bar code on it.

Turn the item upside down or look on the back. Most stores place the bar code in discrete places that aren't visually obvious but still easy to locate. If the item is a book, check the inside jacket. On an item of clothing, look on the tag, usually attached to the care instructions inside the clothes.

If you fail to find an SKU or a sticker for a bar code, search for another item of the same type. Like items will share SKU numbers. The items must be exactly the same. Meaning, they must be the same brand, same size, shape, materials, colors, quality and price. If you find such an item look for the bar code on it, move on to Step 4 if you do not.

Look for a label for the item on the shelf where you found it. If there are no other items like it on the shelf, the item might be misplaced within the store. Labels on the shelves will usually have a bar code on them.

Ask a customer service representative or sales representative. If you can find no one in the store, seek help at the information desk, usually located near the front of the store.