When selling on Amazon, two of the most commonly used product identifiers are the ASIN and the FNSKU.
While they may seem similar, they serve very different purposes in Amazon’s inventory system.
🏷️ What is an ASIN?
ASIN stands for:
Amazon Standard Identification Number
An ASIN is Amazon’s product identifier for items in its catalog.
📦 Key Facts About ASINs
Shared across all sellers selling the same product
Used to identify a product listing in Amazon’s catalog
Usually 10 characters long
Example:
B08N5WRWNW
👉 If multiple sellers sell the same product, they typically share the same ASIN.
🏷️ What is an FNSKU?
FNSKU stands for:
Fulfillment Network Stock Keeping Unit
An FNSKU is Amazon’s unique barcode used specifically for FBA inventory tracking.
📦 Key Facts About FNSKUs
Unique to each seller
Used for FBA inventory identification
Printed on product labels
Helps Amazon track ownership of inventory
Example:
X001ABC123
👉 Even if two sellers sell the same ASIN, they may have different FNSKUs.
🔍 Main Difference
ASIN | FNSKU |
Identifies the product | Identifies the seller’s inventory |
Shared by all sellers | Unique to each seller |
Used in Amazon catalog | Used in FBA warehouses |
Same product = same ASIN | Same product can have different FNSKUs |
📦 Simple Example
Two sellers both sell the same book.
ASIN:
Both sellers use:
B000123456
FNSKU:
Seller A may have:
X001AAA111
Seller B may have:
X001BBB222
👉 Same product, different inventory ownership.
💡 Why FNSKU Labels Matter
FNSKUs help Amazon:
Track inventory ownership
Prevent seller inventory mix-ups
Process FBA inventory correctly
⚠️ Common Mistake
Many new sellers think:
ASIN = barcode label
👉 But for FBA, Amazon usually requires the FNSKU label on inventory.
🔄 How It Works in AccelerList
Within AccelerList:
ASINs are used when searching/scanning products
FNSKU labels are generated for FBA inventory printing
👉 Both are important during the listing and shipment workflow.
✅ Summary
ASIN identifies the product in Amazon’s catalog
FNSKU identifies the seller’s specific FBA inventory
They work together to help Amazon manage product listings and inventory ownership accurately.