When you import products into the Products Catalog, 3Dsellers uses a match and merge process to avoid creating duplicate catalog entries. Understanding how this works helps you import cleanly and fix issues when they come up
How matching works
When importing, 3Dsellers compares each incoming product against existing catalog products using a field you choose — by default, SKU. If a match is found, the product is merged into the existing catalog entry. If no match is found, a new product is created.
You can match by: SKU, Title, UPC, EAN, ASIN, MPN, or ISBN. You can also add a second field for more precise matching (for example, SKU + Title).
What "merge" means
When a match is found, 3Dsellers updates the existing catalog product with the incoming data. Depending on your settings, this can include title, description, pricing, images, inventory, and custom attributes. If you check Override existing product with the new data, the incoming values will overwrite what's already in the catalog.
What are duplicate SKUs and why do they cause problems?
A duplicate SKU occurs when two or more listings on the same selling channel share the same SKU. Since 3Dsellers uses SKUs to match and sync listings with catalog products, each SKU must be unique per channel. If duplicates exist, 3Dsellers cannot reliably link the listing to the correct catalog product, so those products cannot be imported.
How to find and fix duplicate SKUs
After an import, any products that couldn't be imported due to duplicate SKUs are flagged automatically.
To fix them:
Go to Products Catalog → Import → Duplicate Products.
You'll see a list of channels with duplicate SKU counts.
Click View and Fix next to the affected channel.
You'll be taken to the Duplicate SKU segment inside Listings Manager, where all affected listings are grouped.
From there you have several options:
Edit the SKU manually using the pencil icon to give each listing a unique SKU.
Use Auto Fix Duplicate SKUs to let 3Dsellers assign unique SKUs automatically.
Use SKU Generator to apply a custom SKU pattern across selected listings.
If the listings are genuinely the same product and the duplication is intentional, click Mark as not Duplicate SKU.
Once SKUs are unique, re-import the products into the catalog.
Tips
If you sell the same physical product across multiple channels (e.g., eBay US and eBay UK), each channel connection is treated separately — duplicate SKU rules apply per channel, not globally.
Using Auto Fix is the fastest option for large batches, but review the results if SKU naming matters for your workflow.
The Don't create new products option during import is useful if you only want to update existing catalog products and avoid adding anything new.
Troubleshooting
1) The number of catalog products is lower than the number of listings I imported
This is expected behavior when multiple listings share the same SKU or match on the same field. When 3Dsellers finds a match, it merges the incoming listing into the existing catalog product rather than creating a new one. So if 5 listings all have the same SKU, they will all merge into a single catalog product. The catalog count reflects unique products, not total listings.
If this is not what you intended, check whether your listings have truly unique SKUs before importing. You can use the Duplicate SKU segment in Listings Manager to review.
2) A product was imported but it's not linked to the listing
This can happen if the match field used during import (e.g., SKU) does not exactly match the SKU on the live listing. The catalog product gets created but the listing-to-product link is not established. Check that the SKU on the listing in Listings Manager matches exactly what was imported — including spacing, capitalization, and special characters.
3) The import ran but nothing changed in the catalog
If Override existing product with the new data was not checked, and a matching product already exists, 3Dsellers will merge without overwriting existing values. The import technically succeeded but the catalog data stayed the same because the existing values were preserved. Re-run the import with Override enabled if you need to update existing products.
Also check that Don't create new products was not enabled — if it was, only existing products are updated and no new ones are created, which can make it appear as if nothing happened.
4) Inventory didn't update after import
Inventory is only imported if the source listing has available quantity data and the import settings are configured to include inventory. Check the Import new products inventory to setting in the import dialog — if no warehouse is selected, inventory will not be imported. Also note that if a product already exists in the catalog and Override is off, the existing inventory value is kept.
5) Some products were imported but others were skipped
Products are skipped when they have duplicate SKUs that couldn't be resolved, or when Import only products with available quantity is enabled and some listings have zero stock. Check the Duplicate Products page and your import settings to identify which products were excluded and why.
6) A product appears in the catalog but shows the wrong title, price, or images
If Override was enabled during a previous import, the catalog product may have been overwritten by data from a different listing than expected — particularly if multiple listings matched on the same field. Review the match field being used and ensure it uniquely identifies the intended product. If needed, edit the catalog product manually or re-import with more specific match criteria.
7) After fixing duplicate SKUs, the product count still doesn't match
Fixing duplicate SKUs in Listings Manager only resolves the SKU conflicts — you still need to re-run the import after fixing them. Go back to Products Catalog → Import and import again. The Duplicate Products page should clear once all SKUs are unique and the import completes successfully.
What's coming: Manual product merging
We're adding the ability to manually merge catalog products directly from the Products Catalog. If two or more products ended up as separate catalog entries but should be one, you'll be able to select them and merge them in a few steps — no re-import needed.
The merge flow will walk you through choosing a primary product (which is kept), resolving any channel conflicts, reviewing product data, and confirming the merge. All other selected products will be merged into the primary and removed from the catalog.
Stay tuned for this update.