eBay SKU

SKUs are yours to design. Most sellers encode something useful: a source batch, a storage location, a category prefix, and a sequence number. The important properties are uniqueness and stability — a SKU that changes is a SKU that can't be reconciled against a shelf.

In eBay's Inventory API model, the SKU is the primary key for an inventory item. Offers reference it, and revisions target it. That makes SKU hygiene a practical concern rather than a bookkeeping preference: duplicate SKUs create ambiguity about which physical item a listing represents.

When importing listings from a CSV, watch for duplicates. HumCity's CSV import creates new drafts and does not deduplicate by SKU, so importing the same file twice produces two drafts for the same item.