If you are managing inventory flows, selling bulk wholesale goods, or shipping products to international fulfillment centers, you already know that labeling is the hidden bottleneck of e-commerce. When an order drops, the last thing you want is a delay because a barcode won't scan or the format is rejected by the warehouse.
Table of Contents
The E-Commerce Barcode TL;DR
Amazon FBA requires an FNSKU (Code-128 format) for internal tracking, while physical retail stores require a UPC-A (12-digit numeric). To scale Shopify or Amazon operations, sellers should export their SKU lists as CSVs and use a bulk barcode generator to instantly create continuous PDF rolls perfectly formatted for Zebra or Rollo thermal printers.
1. What Type of Barcode Does Amazon Require?
The FNSKU Rule
Amazon requires a specific barcode format called an FNSKU (Fulfillment Network Stock Keeping Unit) for products sent to their fulfillment centers. The FNSKU label must use the Code 128 barcode symbology and clearly display the scannable barcode, the alphanumeric FNSKU underneath it, and the product title.
Only need FNSKU labels? Go straight to the dedicated FNSKU generator →
While you can pay Amazon to label your products for you (FBA Label Service), it actively eats into your profit margins. If you are shipping hundreds of units, the most cost-effective method is to export your FNSKU list from Seller Central as a spreadsheet.
You can then drop that file into an Excel to Barcode Generator to automatically create a printable PDF roll of Code 128 labels for your exact shipment. No manual copy-pasting required.
2. Converting Shopify SKUs into Printable Barcodes
If you fulfill your own Shopify orders, your internal SKUs need to be translated into physical labels for your pick-and-pack team. To convert Shopify SKUs into printable barcodes:
- Export your active inventory list from Shopify as a CSV file.
- Upload this file into a secure bulk barcode generator workspace.
- Select the Code-128 format (because Shopify SKUs often contain letters and dashes).
- Configure your thermal label dimensions (e.g., 50x30mm) and download the batch as a print-ready PDF roll.
Many store owners make the mistake of typing these out one by one. If you have hundreds of product variants (sizes, colors, styles), utilizing a batch generator ensures zero data-entry errors.
3. What is the difference between UPC and Code 128?
This is the most common point of confusion for new e-commerce sellers. They serve two entirely different purposes in the supply chain.
| Feature | UPC-A (Retail) | Code-128 (Logistics) |
|---|---|---|
| Allowed Data | Strictly Numbers Only | Letters, Numbers, Symbols |
| Required Length | Exactly 12 Digits | Variable (Any Length) |
| Primary Use Case | Physical Store Checkout (Target, Walmart) | Amazon FBA, Internal Warehouse SKUs |
If your products are going to physical retail shelves, you must use a GS1-registered UPC. However, if you are moving boxes internally, tracking pallets, or sending goods to Amazon, Code-128 is the undisputed champion due to its alphanumeric flexibility.
4. The High-Volume Seller Workflow
As an Amazon seller or Shopify merchant, scaling your business means moving away from manual tasks. When you receive a massive wholesale shipment that needs to be prepped and shifted to a fulfillment center, you need an automated process:
Export the Data
Pull your active shipping plan or inventory list directly from your e-commerce platform (Shopify, WooCommerce, or Amazon Seller Central) as a CSV.
Automate the Batch
Drop the file into our main bulk barcode workspace. Set your default quantity, and the system automatically reads your rows and multiplies the labels instantly.
Print Directly to Thermal
Download a continuous PDF roll perfectly calibrated for your Zebra or Rollo hardware. This prevents skipped labels and fuzzy, unscannable lines.
5. Frequently Asked Questions
Can I print multiple barcodes at once from a CSV file?
What size should a standard thermal barcode label be?
FBA Seller?
Instantly map your Amazon inventory list to FNSKU barcodes. No manual entry. No software downloads.
