Link variants across products by SKU or barcode

Last updated 30 October 2026

Sometimes the same item is listed in more than one product: a seasonal listing, a gift edition, a personalised version, or a second listing with a different title. Shopify counts stock per variant, so each listing has its own number even though there is one item on the shelf. Here is how to find those listings and keep their stock matched.

Why the same item ends up in two products

In every case the shelf holds one stock of the item, but Shopify shows two numbers. A sale in one listing does not lower the other, so you can sell stock you no longer have.

  • A seasonal or gift edition of an item you already sell.
  • A personalised or monogrammed version made from the same blank item.
  • A second listing with a different title, description or collection.
  • Products created at different times, by different people or by an import.

Find the matching variants

The SKU (your item code) and the barcode are the most useful clues, because variants of the same item usually share one. In the Shopify admin you can search your products or inventory for a SKU or barcode and see every variant that carries it. Variants with the same SKU or barcode in different products are your candidates.

Check each match yourself before you treat two variants as one item. Two variants can share a code by mistake.

Link them in Douplo

Douplo looks for variants that share a SKU or barcode and shows them as suggestions. Open Suggestions, find the pair, and press Use this. The Create link screen opens with those variants already filled in. Nothing is written from a suggestion.

You can also build a link yourself. Open Links, press Create link, then either choose variants from any of your products or type their SKUs or barcodes and press Find.

  • Name the link so you can find it later.
  • Check the locations it covers. By default that is every location where all the variants are stocked, or only the ones you pick from those. Stock is matched location by location and never moves between locations.
  • Review the screen: it shows each variant's stock before and after. Pick the starting number you trust.
  • Press Create link. Nothing starts until you do.
  • Within 2 minutes of creating a link, and if stock hasn't moved since, you can undo it.

After the link is on

When the stock of one variant in the link changes at a location, Douplo sets the other variants in the link at that location to the same number. The link's page tells you if stock matches. On a link's page, Check now compares the variants without changing anything, and Change stock sets a new number for all of them. Every change is listed with its reason.

  • A link can hold up to 50 variants.
  • Douplo changes inventory quantities only, never products, prices or orders.
  • The Free plan keeps up to 3 links on. Pro is $1.99 a month for unlimited links, billed through Shopify.

Things to check first

  • Only link variants that are truly the same item. Different sizes or colours should keep separate counts.
  • Fix wrong or duplicate codes before you link, so a suggestion does not pair two different items.
  • The other variants are updated after a sale, not at the same instant. For very scarce items keep a small safety buffer.

Douplo links Shopify variants that are the same item, in one product or across products, so their stock stays matched, location by location. Get it on the Shopify App Store.

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