A SKU (Stock Keeping Unit) is a unique ID you assign to each product variant. It's how you track stock, pull accurate sales reports, and answer "do we have this in red, medium?" without walking the warehouse.
How do I create a good SKU?
Build it from segments — category, then attributes like color and size, then a unique identifier. Keep the codes consistent across products, skip leading zeros and ambiguous characters, and keep it short enough to type without mistakes.
What's the difference between a SKU and a UPC?
A SKU is internal and you design it. A UPC is a standardized code assigned through GS1 that's the same wherever the product sells. Don't substitute one for the other.
Where do I find a SKU?
On physical products, near the barcode on the packaging or label. Online, on the product detail page near the price, or in your store's admin and on invoices and packing slips.
What are the most common SKU mistakes?
Using manufacturer codes as SKUs, starting with a zero, using look-alike characters like O and 0, and copying another brand's system instead of building around your own inventory.
Should I hand SKU management to a 3PL?
Once volume makes picking and stock-counting a daily time sink, yes. A good 3PL maps to the SKUs you already use, syncs stock across your channels, and ships without you touching a label.
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