Understanding the SKU Linking Process

Updated July 2026 · Getting Started

Overview

When you connect your selling platforms, LinkSyncSell imports all your product listings. The next step is grouping those listings together so the same product across different platforms is recognized as one item - not five separate things.

This grouping happens automatically through SKU matching. If your Shopify store and your Amazon listing both have a listing with the SKU CANDLE-VAN-8OZ, LinkSyncSell sees that shared SKU and links those two listings under a single Master Product automatically. No manual work needed.

How Automatic Linking Works

Here's what happens behind the scenes after you connect a platform:

  • LinkSyncSell imports your listings. Every product and variant from your connected platforms is pulled into LinkSyncSell.
  • LinkSyncSell reads the SKU on each listing. Each variant's SKU is examined.
  • LinkSyncSell looks for matches across platforms. If the same SKU appears on a listing from Platform A and a listing from Platform B, those listings are flagged as the same product.
  • Matching listings are grouped under one Master Product. The linked listings all live under one Master Product record in your catalog. Each individual listing is called a Platform Listing, and each matched variant is called a Master Variant.
  • No duplicates per platform allowed. Each Master Product can only have one listing per platform. If two listings from the same platform share a SKU, that's flagged as a duplicate and needs your attention.
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Note: Automatic linking happens when you first connect a platform and whenever new products are imported. It does not require any action from you as long as your SKUs are consistent.

When Manual Linking Is Required

Automatic linking can't do its job in a few situations. You'll need to step in and link manually when:

  • SKUs are missing (blank). If a listing has no SKU, LinkSyncSell has nothing to match on. That listing will be flagged for your attention.
  • Duplicate SKUs exist on the same platform. If two different products on your Shopify store share the same SKU, that's a conflict. LinkSyncSell will flag both and wait for you to resolve it.
  • Different SKUs are used for the same item across platforms. For example, if your mug is MUG001 on Shopify but CERAMICMUG-1 on Amazon, LinkSyncSell treats them as different products. You'll need to manually tell it they're the same.

How to Fix Linking Issues

  • In the left sidebar, go to Catalog > Link Products.
  • Click the Listings that Need Attention tab. This is where LinkSyncSell surfaces everything that couldn't be auto-linked.
  • Review each flagged listing.
  • For each one, choose one of the following:
  • Assign to an existing Master Product - if this listing matches a product already in your catalog, select the correct Master Product to link it to.
  • Create a new Master Product - if this listing doesn't match anything yet, create a new Master Product and add this listing to it.
  • Repeat until all flagged listings are resolved.
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Tip: Work through the "Listings that Need Attention" tab shortly after your initial setup. Resolving these early means your catalog will be clean and accurate from the start.

Best Practices for SKUs

Following these practices will make your linking experience much smoother:

  • Use the same SKU format everywhere. If your SKU is SHIRT-RED-M on Shopify, use SHIRT-RED-M on Tiktok Shop and Amazon too - not shirt_red_m or RED-SHIRT-MED.
  • Never leave SKUs blank if you sell on multiple platforms. Blank SKUs always require manual linking.
  • Avoid spaces and special characters in SKUs where possible. Stick to letters, numbers, and hyphens. Some platforms handle special characters differently, which can cause matching failures.
  • Check for duplicates before importing. Before connecting a platform, scan your product list for any two products that accidentally share a SKU. Duplicates will create conflicts.
  • Keep a SKU reference spreadsheet. If you're managing a large catalog, a simple spreadsheet that maps each product to its SKU (and confirms it's consistent across platforms) saves a lot of headaches.

Tips & Notes

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Tip: If you're setting up SKUs for the first time, keep them short, consistent, and human-readable. A format like [CATEGORY]-[COLOR]-[SIZE] (e.g., TOTE-BLK-LG) is easy to remember and works well across platforms.

Troubleshooting

My products aren't auto-linking even though my SKUs look the same.

Check for hidden characters, extra spaces, or capitalization differences - Mug-Blue-001 and mug-blue-001 may be treated as different values. Also note that auto-linking only happens the first time a product is imported (when it has no Master Product assigned yet). If your products were previously imported without SKUs, they already have a Master Product assigned re-syncing after adding SKUs will update the internal grouping ID but will not trigger re-matching. To fix this, you'll need to manually unlink the affected products first (see below), then re-sync.

I have hundreds of unlinked products. Where do I start?

Go to Catalog > Link Products > Listings that Need Attention and sort by platform or product name. Tackle the highest-volume products first. Note that fixing SKUs on the platform and re-syncing will only auto-link products that have never been linked before products that were previously imported (even without a SKU) already have a Master Product assigned and won't be re-matched automatically. For those, you'll need to unlink them manually first, then re-sync.

I linked a product incorrectly. Can I undo it?

Yes. Go to the Master Product and remove the incorrectly linked listing. Once unlinked, you can either re-link it manually to the correct Master Product, or re-sync the product if it now has a valid SKU that matches another platform's product, it will be auto-linked correctly on the next import.

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