Managing Duplicate SKUs

Federico Pistarini
Federico Pistarini
  • Updated

In this article:

Why does this happen?

Having items with duplicate SKUs in your store may indicate a problem. This may happen when:

  • Creating a new page for the product in your webstore.
  • Connecting an additional webstore.

If orders come in against the new item, but the inventory is associated with the original item, this can cause orders to be held.

SKUs are unique. If the SKU duplication is not intentional and represent the same physical item, they should be merged.

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What happens when merging two items?

When merging items, one of them will be the “main” item and the others will be merged into it:

  • The resulting item will keep the SKU code, scancodes, and scancode aliases of the “main” item.
  • Their history will be combined as if they were always one item.
  • The item history will have a new line titled "Merged duplicate SKUs"
  • The item quantity balance will have been rewritten, adding the quantity of all combined items.
  • Nothing will be lost: orders, history, and shopping cart connections will all reference the “main” item.

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How do I merge items with duplicated SKUs?

There are three ways of merging items with duplicated SKUs:

The DUPLICATE SKUS page allows you to execute an automatic merge of all items that share the same SKU or manually select which should be merged.

Go to Inventory > Browse/Search, and click Duplicate SKU at the top right corner.


Option 1: Auto-merge all items with one click

To merge all items with one click on the Duplicate SKUS page, mark the Auto-merge items with duplicate skus checkbox and click Save.



  • Merged items will keep the SKU of the last product created.
  • Newly-detected SKUs will be merged after a delay of your choosing (the default time is 30 minutes). Why a delay? It allows you to clone products in your shopping cart, and then update to the correct SKU if the product is different.
  • If auto-merge is enabled but your SKUs are not unique, products will ship incorrectly. Whiplash cannot be held liable for mis-ships that occur from incorrect SKU merging.

Option 2: Merge items individually 

You can also perform this operation with any item listed on the Duplicate SKUS page by clicking on Review & Merge:


Then, select which item should be kept as the main item for the SKU; the other items will be merged into it and subsequently disabled:

Option 3: Merge items on the Item Details page

Additionally, items with the same SKU can be merged on the Item Details page.

The SKU Merge button is visible when opening any item and going to the Details tab. Keep in mind this button will be there even if the SKU is not duplicated.


The next screen is just like the Review and Merge option from Option 2:

  • If two or more items share the same SKU, two or more items will be visible on each column.
    Select which to keep and which to merge and disable.
  • Having only one option in each column means the SKU is unique.

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Troubleshooting tips

  • SKUs cannot be merged unless they are identical in every way. A slight variation can cause an incorrect/inaccurate merge.
  • If an existing item is being updated, a new variant for the SKU should always be created. Merging SKUs will not automatically update old SKUs to reflect the new product
  • When the auto-merge checkbox is enabled, the app merges duplicate SKUs into the newest variant.  Subscription services, like ReCharge, create new variants that cannot be matched in our system. When auto-merge is enabled, these new variants can cause an inaccurate or unexpected merge. 
  • To reflect merge changes on items that were already placed in a shopping cart, use the bulk action Set Info From Items.

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Shopify item duplication

While creating items in Shopify, avoid creating products and variants by duplicating products and variants. It's easy to leave the same SKU or barcode and cause confusion when the new items are synced to Whiplash. If Shopify barcodes are set to sync with Whiplash, these can be added as alternate scancodes when the product is first duplicated. Scancodes can be disabled, but this should be avoided since Shopify doesn't prevent duplicate barcodes.

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Title Merge

The Title Merge feature is similar to merging SKUS but for identical items with different titles. For more information, see Title Merge.

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Related questions:

How to I manage duplicate SKUs? 

What happens when I merge two items?