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SKU Uniqueness: Keeping Your Inventory Clean

4 min read

Published May 1, 2026

What Is a SKU and Why Enforce Uniqueness?

A SKU (Stock Keeping Unit) is a unique code you assign to each product in your inventory. It helps you quickly identify products during sales, repairs, barcode scanning, and reporting. When two different products share the same SKU, it becomes impossible to tell which product was actually sold, used, or restocked, leading to inaccurate stock counts and confusing reports.

Tip

Fixmo enables unique SKU enforcement by default for all shops. We strongly recommend keeping it enabled.

How Unique SKU Enforcement Works

When enabled, Fixmo checks every product you create or edit. If the SKU you entered is already used by another product in your shop, the save is blocked with a clear error message showing the conflicting product's name and a link to view it.

  • Two SIMPLE products with the same SKU, blocked
  • Two COMBO products with the same SKU, blocked
  • Two VARIABLE parent products with the same SKU, blocked
  • A SIMPLE product and a COMBO product with the same SKU, blocked
  • A VARIABLE parent and a child of a different parent with the same SKU, blocked

The Parent/Variant Exception

Variable products have a parent item with one or more variant children (e.g., a phone case in different colors). Variants within the same family are allowed to share SKUs, because they belong to the same product.

  • A VARIABLE parent with SKU 'CASE-01' and its children also using 'CASE-01', allowed
  • Children of the same parent sharing any SKU among themselves, allowed
  • A child of Parent A using a SKU from Parent B's family, blocked

Note

The 'family' is defined as one VARIABLE parent and all its direct variant children. COMBO product components are separate products with their own SKUs.

How to Enable or Disable

The setting is found in Settings > Inventory, under the 'SKU Settings' section.

  1. Go to Settings > Inventory
  2. Scroll down to the 'SKU Settings' section
  3. Toggle 'Enforce unique SKU per product' on or off

Warning

If you disable this feature, identifying exact products by SKU in search, reports, or barcode scanning may return multiple results.

Fixing Existing Duplicate SKUs

If you try to enable unique SKU enforcement but your shop already has duplicate SKUs, Fixmo will show you a list of conflicts. You must fix all duplicates before the toggle can be turned on. For each conflict, either change one product's SKU to be unique, or delete the duplicate product.

SKU Uniqueness During CSV Import

When importing inventory via CSV, the same uniqueness rules apply. If a row in your CSV has a SKU that already exists in your shop (or duplicates another row in the same CSV), that row will be skipped with an error message. The rest of the import continues normally.

SKU Comparison Rules

SKU comparison is case-insensitive and trims whitespace. This means 'ABC', 'abc', 'Abc', and ' ABC ' are all treated as the same SKU. Internal spaces and special characters are preserved, 'USB-006' and 'USB 006' are different SKUs.

Frequently asked questions

By default, no. When 'Enforce unique SKU per product' is enabled (the default), each product must have a distinct SKU within your shop. Variants of the same parent product may share the parent's SKU.

Fixmo will block the save and display an error showing which existing product already uses that SKU. You can click 'View conflicting product' to navigate directly to it.

Yes. Go to Settings > Inventory > SKU Settings and turn off 'Enforce unique SKU per product'. A warning will remind you that identifying exact products by SKU becomes difficult when disabled.

SKU uniqueness is enforced at the shop level, not per branch. A product is shared across all branches, there is only one SKU per product, regardless of how many branches stock it.