How to find duplicate barcodes in Shopify
Find variants that share a barcode, decide which item should keep it, and plan any relabeling before changing your catalog.
Why duplicate barcodes need attention
A barcode should identify the item your staff intend to scan. If different variants share a value, the result may be ambiguous. Depending on the app and workflow, staff may need to choose a match or correct an item that was selected incorrectly.
This can lead to wrong stock movements, receiving errors, and misleading sales reports. Duplicates are one possible cause of inventory discrepancies, alongside missed receipts, returns, manual adjustments, and other data issues.
The scanner reads the printed code; the receiving or checkout application decides what product that code matches. Test the actual workflow instead of assuming every scanner or POS handles duplicates in the same way.
How shared codes get into a catalog
- A copied product or CSV import reuses an existing barcode.
- Separate catalog entries represent the same physical item.
- A supplier sends a code that is already used for another item.
- An old code is reused while labels with that code remain in circulation.
Check whether the records represent different products or intentional duplicates of the same item. A shared SKU, by itself, is not enough to prove that two variants should be merged or relabeled.
Find exact duplicates with a product export
- In Shopify admin, open Products → Export and export the products you want to inspect.
- Import the CSV into a spreadsheet with the barcode column treated as text. This preserves leading zeros and long values.
- Locate Variant Barcode, exclude empty cells, and use duplicate-value highlighting or a count formula to flag repeated values.
- Keep the product handle, variant options, and SKU beside each barcode so you can identify every matching row.
- Review each group against your products and physical labels before making changes.
Sorting the barcode column also places repeated values together. If you compare each row with the one above it, remember to include the first row of every duplicate group in your review.
This finds exact matches in that export. It does not diagnose invalid check digits, hidden characters, or codes that were altered by an earlier spreadsheet import. Keep an untouched copy of the original file.
What Markio adds to the check
Markio’s catalog audit groups variants that share a barcode and reports other code issues separately. The report includes missing values, invalid lengths and check digits, and unsupported characters, along with duplicate SKUs and conflicts in Markio’s code records.
Seeing the affected products and stock together helps you investigate the group. A report finding is a reason to review the records; it does not establish that an item has already been sold or received incorrectly.
The audit report is free. You can make corrections in Shopify yourself, or use Markio’s bulk-fix workflow on Pro.
Change codes without losing track of printed labels
- Choose the variant that keeps the code. Check supplier identifiers, stock, existing labels, and connected systems.
- Review replacement codes. Use an appropriate numbering rule and preview the affected variants before applying a batch.
- Relabel the affected stock. Include shelves, boxes, and any stock away from the main location.
- Test in the apps your staff use. Scan representative labels in POS, receiving, and other connected workflows.
On Pro, Markio offers a before-and-after preview and undo for supported bulk fixes. Undo checks current Shopify values and skips conflicts with later edits. It does not undo physical relabeling or changes in another system.
Markio can retain retired codes and resolve configured aliases in its own scanning workflows. Do not assume that an alias automatically works in every third-party scanner app or checkout integration.
Keep the catalog consistent
Check again after large imports, supplier changes, or catalog duplication. Pro can run scheduled audits and email alerts about new findings. Agree on who assigns codes so that a cleanup is followed by a consistent process.
Review duplicate groups before changing them
Markio is coming soon to the Shopify App Store.
Use the free catalog audit to inspect shared codes. Pro adds bulk corrections with previews and undo, plus scheduled checks.