How to Generate UPC Codes to Sell on Amazon, eBay, Google Shopping

Product identifier barcodes help organize the sale of products globally. These tracking numbers provide integrity and trust throughout the supply chain — across dropshipping, ecommerce, and traditional retail alike.

Consumers don’t always know exactly who they’re buying from or what they’re getting. A significant share of counterfeit and knockoff products in digital retail originate overseas, and even Amazon — with its extremely high vetting standards for third-party sellers — is not entirely immune from the problem.

This is one major reason why big advertising platforms like Google, eBay, and Amazon reward you for including these barcodes in your campaign data when running ads to consumers. Today’s article covers the 9 unique types of product identifier barcodes that matter most for dropship retailers — and how they can help you sell more.

First, a Short History of the Universal Product Code (UPC)

Product identifier barcodes — UPC, GTIN, ISBN, EAN, MPN, and others — have existed for a long time. The UPC was invented by Joe Woodland in 1974, well before the rise of ecommerce. There’s almost no retail exchange that occurs today without some form of barcode, whether it’s a major electronics purchase or a pack of breath mints.

While copyright deterrence is just one extreme example of their usefulness, you may be wondering why there are so many variants. UPCs aren’t arbitrary — each code serves a very distinct and separate purpose. If you’re serious about understanding ecommerce, you need to understand the difference between them.

What Is a UPC Code and Why Is It Necessary?

A UPC is always a 12-digit number used to identify each unique product within the United States and Canada only. It’s also known as a GTIN-12. The other major product identifier code — the EAN — is used everywhere else around the globe. And yes, UPCs are different from SKUs. More on that below.

UPCs aren’t just about knowing how many units you have in stock. They track what sells and what doesn’t — for stores online and offline alike.

Product Identifiers Help Organize Products at Scale

Imagine you’re a national retailer with thousands of locations. Your inventory must comply with federal and international standards. And your product line spans thousands or millions of individual items. Any time a purchase is made, both the product and the quantity need to be tracked accurately to ensure sufficient inventory for the retailer and accurate demand forecasting for the manufacturer.

Without a system to track and organize all that, things would be very messy. In the USA and Canada, product information is transmitted by a Universal Product Code (UPC), which allows for accurate electronic scanning and tracking — ensuring efficiency in supply management and forecasting.

UPCs Are Not Required by Law to Sell Online

While UPCs are not required to list a product for sale online, they are typically required by large retail stores and in many international contexts to comply with regulatory standards of pricing and product integrity.

The primary non-profit organization responsible for establishing and authorizing those standards is Global Standards 1 — GS1.org — which currently has offices in over 110 countries. Whether you’re selling on Amazon, eBay, or your own ecommerce storefront running Google Shopping ads, GS1 is the primary authoritative source for both international and domestic barcodes.

How GTINs, UPCs, and MPNs Boost Your Google Shopping Campaign Performance

Google dominates the vast majority of search and paid traffic market share. Many retailers understand that Google Shopping ads are extremely effective — but most beginners are unaware that Google gives your shopping ads priority when you include UPCs in your data feed.

Your Google Shopping ads are determined by the data you submit to Google through your Google Merchant Center account. When you contact legitimate dropship suppliers directly and become one of their official retailers, they don’t always provide UPCs, GTINs, or MPNs to enter into your data feed columns. So what do you do?

One option is to delete those columns and leave them off altogether — which I don’t recommend if you want your ads to perform well. The second, better option is to purchase UPCs at an affordable price from an approved provider for all of your dropship products that are missing them. These can then be entered into the GTIN and MPN fields on your Google Merchants data feed.

Google Merchant Center will then process that data and give your products priority over competing products without UPCs for the same search queries.

You don’t technically need a UPC code to advertise products on Google — but including them significantly increases the likelihood your ads are shown more often and given priority. You can also promote your products on Google for free through Google Surfaces, which shows your products organically across Google properties.

“Google tries to match your product information with the most relevant queries. Strong product identifiers like Global Trade Item Numbers (GTINs), Manufacturer Part Numbers (MPNs), and brand names help increase Google’s understanding of products in your feed. If you don’t supply these attributes, it’s less likely we’ll be able to match your offers to products, and your products are less likely to be shown for relevant queries.” — Google Merchant Center Help

What Is a SKU Number?

The Stock Keeping Unit (SKU) number is used for internal purposes, for any type of product — not just shippable items. A SKU is most commonly 8 digits, but technically can be any string you create to identify any product or service you sell. SKU numbers are for your business only — they’re used to maintain an accurate status of your stock and are numbers your own organization recognizes.

What Is an EAN?

A European Article Number (EAN) fulfills the same function as a UPC in the US, only it adheres to international regulatory standards. It consists of a unique 13-digit number based on a numerical sequence, a product identifier code, a manufacturer code, and a check digit.

Most retail sales — physical or digital — can be transacted using either code since the software that reads each is universal. Many international sellers tend to use EANs in ecommerce to avoid confusion when selling across borders.

What Is a GTIN?

A Global Trade Item Number (GTIN) is an umbrella identifier used by Google, eBay, Amazon, Walmart, and Alibaba to match product listings to relevant search queries. GTINs include UPCs (GTIN-12), EANs (GTIN-13), and ITF-14s (GTIN-14). If you don’t supply GTINs in your product listings where they’re available, your products are less likely to appear for relevant search queries. GTINs are required by most major online retail platforms.

What Is an MPN?

A Manufacturer Part Number (MPN) is used to distinguish a particular product from similar ones within a manufacturer’s product line. In instances where a GTIN-12 is assigned to an entire product line, an MPN is then used to target and track sales of a specific individual product within that line.

What Is an ISBN?

The International Standard Book Number (ISBN) is a code of 10–13 digits used by both retailers and libraries to identify a particular book title. It’s a product-specific version of the GTIN structure, applied exclusively to published books.

What Is an ASIN?

An Amazon Standard Identification Number (ASIN) is exclusively for use in Amazon transactions. It consists of a unique 10-character alphanumeric code automatically generated by Amazon to identify products being sold by merchants and third-party sellers on the platform. ASINs are not transferable to other platforms.

What Is an ITF-14 Number?

An ITF-14 is a specific category of GTIN consisting of a block of 14 numbers. It’s used globally to identify multiple quantities of the same GTIN in a bundle — for example, a 12-pack of socks or a 6-pack of soup cans.

What Are GS1 Databars?

Formerly known as Reduced Space Symbology, a GS1 Databar is used to identify promotional coupons and perishable items. Unlike standard barcodes, it doesn’t follow a simple numerical sequence — instead, it’s recognized by both a barcode and an individual QR code for verification. You’ll commonly see GS1 Databars on grocery coupons and fresh food items.

Two Barcode Generator Services

Barcodes are generated by applying either directly to GS1.org — who will assign you a company prefix number and a unique code per product based on your merchandise and location — or from an approved seller of GS1 codes. They’re not generated for free.

1 — Generating Barcodes From GS1

GS1 typically requires a minimum purchase of at least 100 codes starting at $750 USD — and that’s before annual renewal fees. Here is a snapshot of GS1’s pricing structure at time of this writing:

As you can see, GS1 is not just a one-time cost — it carries an ongoing annual renewal. For most beginner dropship retailers, GS1’s full pricing structure is too costly to start with.

2 — The Affordable Alternative to GS1 Barcodes for eBay, Amazon & Google

Selling products on eBay without a UPC is possible and not required. On Amazon, however, a UPC is required to list your product. And while Google doesn’t require GTINs/MPNs/UPCs, you get significantly better traffic and ad priority by providing them.

To solve this affordably, you can purchase UPCs from Barcodes Talk, an approved provider, to secure the specific codes you need for your product listings. Once your purchase is complete, you own the UPCs 100% without recurring renewal fees. Each UPC is one unique product identifier — like a unique thumbprint for that specific product.

The GS1 Class Action Lawsuit Background

In 2002, the UCC (now known as GS1) settled a major class action lawsuit. As a result of that settlement, GTINs purchased from approved third-party providers can be legally owned by you without renewal fees and used as you see fit for your products.

Summary

The product identifiers and barcode types covered in this article are an underappreciated but genuinely important part of running a serious ecommerce or dropship business. Now that you know the difference between UPCs, GTINs, MPNs, EANs, SKUs, ASINs, ISBNs, ITF-14s, and GS1 Databars — you’re ready to move forward with confidence.