How products and stock items relate

Last updated: June 20, 2026

What this is

A product (what you sell) and a stock item (the SKU you hold) are not the same thing, and the link between them is flexible on purpose. Understanding it lets you model packs, bundles and pick-your-own without duplicating data.

Product → stock item(s)Productwhat you sellSingleMultipleLooseNo stockStock item (SKU)what you holdStock item (SKU)another optionFlexible linkCross-unit + Multiple qtyCombo / package (BOM)Pick the SKU at sale (loose)
One product can map to its stock in several ways simplified mockup

Product is not SKU

A stock item is a thing you physically hold and value. A product is a line a customer can buy. One product can point at one SKU, several SKUs, or none at all. A product sets how it handles stock:

  • Single item. The product is one specific SKU.
  • Multiple item. The product offers several set SKUs to choose between.
  • Loose item. The actual SKU is chosen at the point of sale, so the seller picks the exact item on the order.
  • No stock. A service or fee that holds no stock at all.

Selling in a different unit

A product can sell in one unit while its stock is held in another. A Multiple qty links the two: it says how many stock units one sold unit draws. So you can hold singles but sell a carton, or hold a roll but sell by the metre, and stock moves by the right amount automatically.

Combos and packages

To sell a bundle, build it as a Bill of Materials: several stock items in set quantities, combined into one sellable package. Components can be required or optional, so a combo can include fixed parts and choices.

Why it is built this way. The same catalogue can carry a plain item, a multi-pack, a pick-your-own line, a kit and a service, each drawing on your stock correctly, without you keeping duplicate records.

Related

  • Set up a product
  • Set up a stock item
  • Build with Bill of Materials