In short. Enter a product's SKU and barcode identifier in Product data > Inventory, or open an individual variation to enter its own values.
Definition: As of 17 October 2026, WooCommerce places product identifiers in Product data > Inventory: a stock-keeping unit (SKU) for tracking a product, and a separate barcode field labelled "GTIN, UPC, EAN, or ISBN". Variations also have identifier fields in their individual settings.
Key facts
- WooCommerce's product editor reference lists SKU as optional and requires each SKU to be unique across the store.
- The barcode scanner documentation locates the barcode field in the product's Inventory tab and recommends it for standard retail barcodes.
- The Variable Products guide documents inheritance: a blank variation SKU or barcode field uses the corresponding product-level value when one exists.
Where are the fields in the editor?
WooCommerce's product management documentation links to its editor settings reference for the fields on the Edit Product page. For an existing product, the documented route begins at Products > All Products, followed by Edit on the relevant product.
The editor settings reference places SKU in the Inventory section of Product data. The route to the identifier fields is:
Products > All Products > Edit > Product data > Inventory
After editing a published product, Update saves the changes. For a draft, Save Draft saves the work. The same reference explains that themes and page builders can change the editor's appearance; Screen Options controls the visibility of some panels.
Which identifier belongs in each field?
The Inventory code reference expands the barcode field's abbreviations: Global Trade Item Number (GTIN), Universal Product Code (UPC), European Article Number (EAN), and International Standard Book Number (ISBN). These names appear together as the label of a single input.
WooCommerce's barcode guidance recommends the barcode field for standard retail codes, leaving SKU available for a human-readable identifier. It instructs stores to enter the complete barcode, including a check digit or country code where the format uses one.
For stores using the Google for WooCommerce extension, its GTIN documentation recommends the built-in global unique ID field for syncing GTIN data to Google Merchant Centre. That documentation directs entry through the product's Inventory tab.
Where are identifiers for individual variations?
A variable product offers options such as different sizes or colors. In WooCommerce's variation workflow, opening Product data > Variations and expanding an individual variation exposes its settings, including SKU and the barcode identifier.
The guide allows a variation SKU to remain blank. Where the parent product has a SKU, the variation then uses that value. The same fallback applies to the product-level GTIN. A variation with its own identifier therefore needs that value entered in its individual settings. Save changes at the bottom of the variations panel saves the variation edits.
Related terms
- Product identifiers
- How do I create a variable product in WooCommerce?
- How do I add missing Google feed attributes in WooCommerce?
FAQ
Must I assign a SKU to every product?
You can leave it blank: WooCommerce's editor reference marks SKU as optional. When you enter a SKU, it must be unique across the store.
Can I enter an ISBN ending in X?
Yes. WooCommerce's barcode documentation explicitly permits X as the final check digit of an ISBN-10, with 157249042X as its example. You can enter uppercase or lowercase X; the field preserves the case entered.
Sources
- WooCommerce, "Adding and Managing Products", undated
- WooCommerce, "WooCommerce Product Editor settings", undated
- WooCommerce, "Barcode and QR code scanner", undated
- WooCommerce, "Variable Products", undated
- WooCommerce, "WooCommerce Code Reference: html-product-data-inventory.php", 9 October 2026
- WooCommerce, "GTIN", undated
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