An X00 barcode on Amazon usually refers to an FNSKU label used in FBA to identify seller-specific inventory.Instead of relying only on a manufacturer barcode, Amazon assigns this code to track units at the seller level, improving inventory accuracy and reducing mix-ups.

If you sell through FBA, understanding how the X00 barcode works can prevent receiving errors, delays, and unexpected fees.

What Is an X00 Barcode?

An X00 barcode represents an Amazon barcode (FNSKU) linked to a specific seller's inventory.

Technical Composition

Amazon X00 barcodes are typically generated using Code 128, a compact barcode format designed for fast and reliable scanning in warehouse environments.

The “X00” prefix indicates that the label is an Amazon FNSKU, which is used to identify seller-specific inventory within FBA.

The remaining characters form a unique code assigned by Amazon, linking the product to a specific seller and SKU.

Each unit with this label is tied to your account, not just the product listing.

This allows Amazon to distinguish your inventory from other sellers offering the same ASIN.

Why Amazon Uses X00 Barcodes

Amazon manages millions of products and requires multiple identifiers to keep inventory organized.

Each layer serves a different purpose:

•   Product identity (UPC / EAN)

•   Catalog identity (ASIN)

•   Seller inventory identity (FNSKU / X00)

The X00 barcode exists to solve one problem: who owns this exact unit inside FBA.

X00 vs B00 vs UPC: What's the Difference?

This is where most confusion starts—because these codes look similar but serve completely different purposes.

A simple way to understand it

•   UPC answers: What product is this in the retail world?

•   ASIN / B00 answers: What product is this in Amazon's catalog?

•   X00 / FNSKU answers: Whose specific FBA inventory is this unit?

That distinction matters because Amazon uses each layer for a different part of its system.

X00 vs B00: Why Sellers Keep Mixing Them Up

Many sellers see X00 and B00 on the same product and assume they mean the same thing.

They don't.

A B00 code identifies the product, while an X00 barcode identifies the seller's specific inventory.

This means multiple sellers can share the same B00 (same product), but each seller's units can have a different X00 label.

Mixing them up can cause real problems in FBA operations, such as:

•   incorrect scanning during receiving

•   inventory mismatch

•   tracking errors

In warehouse workflows, scanning the wrong barcode can affect how inventory is stored, counted, or assigned.

Manufacturer Barcode vs Amazon Barcode

When sending inventory to FBA, you typically choose between:

Manufacturer barcode

•   uses UPC / EAN already on packaging

•   simpler for production

•   works across multiple sales channels

Amazon barcode (X00 / FNSKU)

•   assigned by Amazon

•   required in certain categories

•   ties inventory directly to your seller account

This decision affects logistics, cost, and inventory control.

When Do You Need an X00 Barcode?

You need an X00 barcode when your SKU is set to use Amazon labels.

This typically applies when:

•   the product is not eligible for manufacturer barcode use

•   Amazon requires FNSKU labeling

•   the category involves regulated or consumable items

Even when optional, many sellers still choose X00 barcodes for better control.

They help:

•   prevent inventory mixing across sellers

•   improve traceability

•   separate batches or SKUs

•   reduce quality risks

This approach is especially useful for private label brands or sellers who want tighter inventory control.

When Manufacturer Barcodes Make More Sense

Manufacturer barcodes still work well in simple setups.

They are ideal when:

•   products already have compliant GTIN labels

•   you sell across multiple platforms

•   you want fewer prep steps

•   inventory mixing is not a concern

However, this approach reduces control over how inventory is handled inside FBA.

Common X00 Barcode Mistakes

Most issues come from small errors.

❌ Multiple barcodes visible

Only one barcode should be scannable.

❌ Poor label quality

Blurry or curved labels reduce scan success.

❌ Wrong barcode type used

Mixing X00 and UPC incorrectly causes confusion.

❌ Incorrect placement

Labels too close to edges or folds can fail scanning.

❌ Assuming X00 equals B00

They serve completely different purposes.

How to Check if Your SKU Uses an X00 Barcode

You can verify this inside Seller Central.

Steps:

•   go to Manage Inventory

•   add the FNSKU column

Then check:

•   FNSKU starts with X00 → Amazon barcode

•   FNSKU matches ASIN → manufacturer barcode

This is the fastest way to confirm your setup.

How to Print X00 Barcode Labels Correctly

Printing quality directly affects receiving success.

Best practices:

•   use high-resolution printing

•   keep labels flat and visible

•   avoid corners and edges

•   maintain a clear contrast

•   ensure consistent placement

Size guideline:

•   minimum: 1 x 2 inches

•   maximum: 2 x 3 inches

Always test scan before shipping.

If you're managing multiple SKUs, you'll often need more than just FNSKU labels.

Many sellers use a batch barcode generator to create UPC, EAN, or internal SKU barcodes in bulk. This makes it much easier to keep inventory organized, especially when working across different platforms or large product catalogs.

Does Amazon Charge for X00 Labels?

If Amazon applies labels for you, a per-unit fee may apply (commonly around $0.55, though this can change). Sellers should always confirm current pricing in Seller Central.

This is why some sellers prefer manufacturer barcodes when allowed—the choice impacts both operations and overall unit costs.

Quick Decision Table: Should You Use X00 or Manufacturer Barcode?

Final Thoughts

An X00 barcode gives Amazon a clear way to track your inventory at the seller level.

It connects each unit to your account, not just the product listing.

Once you understand how X00, B00, and UPC work together, labeling decisions become much easier.

FAQs

What is an X00 barcode on Amazon?

An X00 barcode usually refers to an Amazon FNSKU label used to identify seller-specific inventory in FBA.

Is X00 the same as B00?

No. X00 relates to FNSKU labels, while B00 is commonly associated with ASIN patterns in Amazon's catalog.

When do I need an X00 barcode?

When your product requires Amazon labeling or when you want seller-specific inventory tracking.

Can wrong X00 labels cause issues?

Yes. Incorrect or missing labels can lead to receiving delays or inventory errors.

Can I switch from UPC to X00 later?

In many cases, switching requires creating a new SKU rather than modifying an existing one.