UPC & EAN Barcodes for Amazon: Complete Seller Guide (2026)

If you're setting up your first Amazon product listing, you've probably hit the same wall every new seller hits: Amazon asks for a "Product ID" and gives you a dropdown full of acronyms — UPC, EAN, GTIN, ISBN — with zero explanation of which one you need or where to get it.

The short version: you need a barcode. The long version is messier. There's a difference between UPC and EAN that trips people up. There's the GS1 registration question — do you actually need it, or can you buy cheap barcodes off eBay? (Spoiler: Amazon cracked down on that in 2018.) And then there's the whole FBA labeling process, which has its own set of rules about where to stick labels and what size they need to be.

This guide covers all of it. By the end, you'll know exactly which barcode format your product needs, how to get legitimate GS1-registered numbers without overpaying, and how to print labels that won't get your shipment rejected at the Amazon fulfillment center dock.

UPC vs EAN vs GTIN: What's the Difference?

These three terms get thrown around interchangeably, and it causes no end of confusion. Let's sort them out properly.

UPC-A (Universal Product Code)

The UPC-A is a 12-digit barcode. It's the one you see on literally every product in a US grocery store. The format breaks down like this: the first 6-10 digits are your GS1 Company Prefix (tied to your business), the next 1-5 digits are your item reference number (you assign these to individual products), and the final digit is a check digit computed from everything before it.

If you're selling on Amazon.com (the US marketplace), the product ID field defaults to UPC. Amazon accepts both 12-digit UPCs and 13-digit EANs, but the US catalog system is built around UPCs, so that's what most domestic sellers use.

EAN-13 (European Article Number)

The EAN-13 is the 13-digit version of the UPC. It's the retail standard everywhere outside North America. The structure is nearly identical to UPC-A — the only real difference is a 3-digit GS1 country prefix prepended to the beginning. A UPC starting with "0" is mathematically identical to an EAN-13, because 0 is the US/Canada country code. That's why most barcode scanners can read either format without issue.

If you're listing products on Amazon UK, DE, FR, IT, ES, or any European marketplace, the product ID field will typically expect an EAN-13. Some categories on Amazon US also accept EANs for international products.

GTIN (Global Trade Item Number)

GTIN is the umbrella term. A UPC is a GTIN-12. An EAN-13 is a GTIN-13. An ISBN is a GTIN-13 for books. When Amazon asks for a "GTIN" in the product ID field, it's using the generic term — you just enter whatever format your product uses. The system figures out the rest.

Why You Can't Skip GS1 Registration

There used to be a gray area here. Before 2018, you could buy legitimate-looking UPCs from third-party resellers (companies that had purchased huge GS1 prefixes and were reselling individual barcodes for $5-10 each). It was cheaper than getting your own GS1 membership, and for a while, Amazon didn't check.

That changed. Amazon now validates every product ID against the GS1 database in real time. When you enter a UPC or EAN in your listing, Amazon looks up the GS1 Company Prefix and checks whether it's registered to your seller account name. If the prefix belongs to a different company — or worse, to a defunct reseller — your listing gets flagged and suppressed. You'll get a notification that says something like "The UPC provided does not match the product."

Getting a suppressed listing reinstated is a pain. You have to get your own GS1 prefix, update the product ID, and submit an appeal — which can take days or weeks. During that time, your product is invisible to shoppers, any ads you're running stop, and you're losing sales. It's not worth the risk.

How GS1 Registration Actually Works

GS1 is a non-profit organization that manages barcode standards globally. You don't "buy" barcodes from them — you lease a Company Prefix, which gives you the right to generate barcodes from a specific range of numbers assigned to your business. The prefix length determines how many barcodes you can create:

For most new Amazon sellers with a handful of products, the 10-barcode package at $250 is plenty. If you're building a private label brand with a growing catalog, go with 100 barcodes ($250) to give yourself room. The annual renewal fee is the same regardless of prefix size.

Registration is done through your local GS1 member organization. In the US, that's GS1 US (gs1us.org). In the UK, it's GS1 UK. In Germany, GS1 Germany. Each country organization handles its own registration, but the barcodes work globally — a UPC from GS1 US scans perfectly fine in a European store.

How to Generate and Print Your Barcodes

Once you have a GS1 Company Prefix, you can assign item reference numbers to your products and generate the actual barcode images. Here's the process from start to finish:

Step 1: Assign Your Product Numbers

Take your GS1 Company Prefix (let's say it's 8 digits: 01234567) and append your item reference numbers. If your prefix is 8 digits, you get 3 digits for item references — so 001, 002, 003, and so on. That gives you the first 11 digits of your UPC. The 12th digit (the check digit) is calculated automatically using the modulo-10 algorithm.

Keep a spreadsheet of every barcode you assign, what product it maps to, and when you created it. This sounds obvious, but you'd be surprised how many sellers lose track and accidentally assign the same UPC to two different products — which creates a mess on Amazon because the system thinks they're the same listing.

Step 2: Generate the Barcode Image

You need a barcode image file that you can print on product labels. The image must meet Amazon's requirements: correct format (UPC-A or EAN-13), proper quiet zones (blank margins on both sides), and sufficient resolution.

You can use our free barcode generator to create UPC-A, EAN-13, Code 128, and Code 39 barcodes instantly. Enter your digits, pick the format, and download the image as a high-resolution PNG. The check digit is calculated automatically — you just enter the first 11 digits (UPC) or 12 digits (EAN) and the tool adds the correct check digit.

Step 3: Print at the Right Size and Quality

Amazon has specific printing requirements for FBA labels:

• Resolution: Minimum 300 DPI. Anything lower causes bar edges to blur and scanners to misread.
• Label size: Amazon's standard FBA label is 1" x 2" (25mm x 50mm). You can print larger, but not smaller.
• Quiet zone: At least 5mm of blank white space on both sides of the barcode bars.
• Color: Black bars on white background only. Never use colored labels or red ink — laser scanners can't see red.
• Human-readable text: The digits should be printed below the barcode in a readable font, at least 8pt.

Most sellers use a thermal label printer like the Zebra ZD421 or the Rollo X1470. These printers output at 203 DPI minimum (many go up to 300+ DPI) and use direct thermal technology — no ink needed. A roll of 1" x 2" labels costs about $10-15 for 1,000 labels, which works out to about a penny per label.

Step 4: Apply Labels Correctly

For FBA, you have two labeling options:

• Seller labeling: You print and apply the FNSKU label (not the UPC — more on this below) to each unit before sending inventory to Amazon. You cover the original manufacturer barcode with the FNSKU label.
• Amazon labeling service: You send products to Amazon without labels, and Amazon applies labels for you at $0.30 per unit. This is convenient but adds up quickly if you're shipping hundreds of units.

The label must be placed on a flat, smooth surface of the packaging. It can't wrap around an edge, fold over a corner, or sit on a curved surface. If the product already has a manufacturer barcode on it, your FNSKU label must completely cover it — otherwise the scanner might read the wrong code.

The FNSKU vs UPC Distinction (This Trips Everyone Up)

Here's something that confuses nearly every new FBA seller: the barcode on your product packaging and the label Amazon requires on each unit are not the same thing.

Your UPC or EAN is the retail product identifier. It goes on the product packaging itself, the kind that would be scanned at a Walmart checkout. You use it when creating your Amazon listing — it's the "Product ID" you enter in the listing setup.

The FNSKU (Fulfillment Network Stock Keeping Unit) is Amazon's internal identifier. Once your listing is active, Amazon assigns an FNSKU to each product. You print this on a separate label and apply it to each unit before sending inventory to FBA warehouses. The FNSKU tells Amazon's warehouse scanners which listing, which seller, and which condition the product belongs to.

If your product's manufacturer barcode is already registered with GS1 and visible on the packaging, you might qualify for Amazon's "Stickerless" commingled inventory — but in practice, most private label sellers still need to apply FNSKU labels to prevent their inventory from being mixed with other sellers' units of the "same" product.

Common Barcode Rejection Reasons (and How to Fix Them)

Amazon rejects listings and FBA shipments for barcode issues more often than most sellers expect. Here are the five most common reasons and their fixes:

1. "UPC does not match the GS1 database"

This means your barcode prefix isn't registered to your seller name. Either you bought barcodes from a reseller (pre-2018 inventory), or there's a name mismatch between your GS1 registration and your Amazon seller account. Fix: Register your own GS1 prefix, update the product ID on your listing, and make sure the company name on your GS1 certificate matches your Amazon legal entity name.

2. "Check digit is invalid"

The last digit of your UPC/EAN doesn't match what the modulo-10 algorithm expects. This happens when someone manually types a barcode number and makes a typo, or when a generator tool doesn't compute the check digit correctly. Fix: Regenerate the barcode using a reliable tool that calculates the check digit automatically. You can verify any check digit manually: multiply odd-position digits by 3, even-position by 1, sum them, and the check digit is whatever number makes the total a multiple of 10.

3. FBA shipment rejected: "Barcode not scannable"

The fulfillment center couldn't read your labels. Usually this means low print resolution, damaged labels (smudged, folded, or wet), or insufficient quiet zone around the barcode. Fix: Check your printer DPI settings (should be 300+), use fresh label rolls, and ensure at least 5mm of blank space on each side of the bars.

4. "Product ID already exists for a different ASIN"

Someone else is already using your UPC on a different Amazon listing. This happens when you buy a product from a supplier who gave you their barcode, but another seller already listed that same product with a different ASIN. Fix: If you're selling a unique variation (different color, size, or bundle), you need a new UPC for that variation. If you're reselling the same product, use the existing ASIN.

5. "Barcode is covered or obscured"

During FBA receiving, the warehouse found that your FNSKU label doesn't completely cover the original manufacturer barcode, or the label is placed on a curved or wrinkled surface. Fix: Make sure your FNSKU label is large enough to fully cover any existing barcode underneath, and place it only on flat surfaces.

Real-World Example: Setting Up Your First Product

Let's walk through the entire process for a hypothetical new private label seller.

Product: Stainless steel water bottle, private label brand "HydroPeak"
Selling on: Amazon US, with plans to expand to Amazon UK
GS1 registration: 10-barcode package, $250 upfront + $160/year renewal

For the UK marketplace, the same seller would use the same GS1 prefix but generate an EAN-13 by prepending a "0" to the UPC (since the US country code is 0). The EAN-13 0012345678901 is functionally identical to the UPC 012345678901. Both scan the same, both are in the GS1 database under the same company prefix.

5 Things Experienced Sellers Do Differently

1. They Register with GS1 Before Sourcing Products

Don't wait until your products are manufactured and sitting in a warehouse to realize you need barcodes. The GS1 registration process takes 1-3 business days, and you need your UPC numbers before your manufacturer can print packaging. Get your prefix early — ideally before you place your first production order — and provide the barcode artwork to your manufacturer so it's printed directly on the packaging.

2. They Keep a Master Barcode Spreadsheet

Every barcode you assign should be logged: product name, variation (color/size), UPC, EAN (if applicable), FNSKU, ASIN, date assigned, and GS1 certificate reference. When you have 50+ SKUs, trying to remember which barcode goes with which product is impossible without a system. Use Google Sheets, Airtable, or even a simple Excel file.

3. They Print Test Labels Before Bulk Runs

Before printing 500 labels, print one and scan it with a phone app or a handheld scanner. Verify that the scanned output matches the intended digits exactly. A misconfigured generator or a wrong DPI setting can produce barcodes that look right visually but scan as the wrong number — and you don't want to discover that after 500 units are labeled and shipped.

4. They Use Code 128 for Internal Operations

For warehouse bin labels, shipping carton labels, and internal inventory tracking, you don't need GS1-registered barcodes. Code 128 is a high-density format that can encode any alphanumeric string — perfect for custom SKU codes, batch numbers, or location identifiers. Our barcode generator supports Code 128 along with UPC-A, EAN-13, and Code 39, all in the same tool.

5. They Budget for Label Printing Equipment

If you're doing FBA, you'll be printing a lot of labels. A thermal printer pays for itself within the first few hundred units compared to paying Amazon $0.30/unit for their labeling service. The Zebra ZD421 ($200-300) and Rollo X1470 ($170-200) are the two most popular options. Add label rolls at $10-15 per 1,000, and your per-unit labeling cost drops to about 1-2 cents.

FAQ: Common Questions About Barcodes for Amazon

Final Thoughts

Getting barcodes right is one of those unglamorous fundamentals that separates smooth launches from chaotic ones. The process isn't complicated — register with GS1, assign numbers to your products, generate clean barcode images, and print labels that meet Amazon's specs — but each step has a way of tripping up sellers who rush through it.

The two biggest mistakes to avoid: buying barcodes from resellers instead of registering your own GS1 prefix, and printing labels at insufficient resolution. Both lead to the same outcome — delayed launches, suppressed listings, and inventory stuck in limbo at fulfillment centers.

Get your GS1 prefix early, keep a clean spreadsheet of every barcode assignment, and always print a test label before running bulk batches. These three habits alone will save you from 90% of barcode-related headaches.

Ready to generate your barcode images? Try our free barcode generator — supports UPC-A, EAN-13, Code 128, and Code 39 with automatic check digit calculation. No signup required.