What a barcode does and why you need one

A barcode is a machine-readable pattern of lines and numbers that identifies a single product. When a scanner reads it, the barcode sends a code to a computer system — usually a point-of-sale register, inventory database, or shipping system — that looks up the product's name, price, or stock location. You need a barcode if you plan to sell a product in a retail store, track it in a warehouse, or ship it through a carrier that uses automated sorting.

The barcode itself is just the visual representation. Behind it sits a number — typically 12 digits for a product sold in North America, or 13 digits in most other countries. That number is called a UPC (Universal Product Code) in North America or an EAN (European Article Number) elsewhere. You generate or purchase that number first, then create the barcode image from it.

If you are selling only online through your own website or a platform like Etsy, you may not need a barcode at all. If you are selling through Amazon, Walmart, Target, or any physical retail location, you will need one. Carriers like UPS and FedEx can generate shipping barcodes for you automatically, but product barcodes are your responsibility.

Key Takeaways

  • A barcode number (UPC or EAN) must be purchased from GS1, the official standards body, or obtained through a reseller — you cannot create a valid number yourself.
  • Once you own the number, you can generate the barcode image using free online tools, barcode software, or design programs like Adobe Illustrator or Canva.
  • The barcode image must meet specific size and print quality standards or scanners will fail to read it, so test it before printing or shipping products.
  • Retail stores and warehouses require barcodes to be on the product packaging in a specific location, usually the bottom right corner, with clear space around it.
  • If you are selling only online or directly to consumers, you may not need a barcode unless the retailer or platform requires one.

Getting a barcode number from GS1

Before you can create a barcode image, you need to own the number that goes inside it. In North America, that number comes from GS1 US (or GS1 Canada if you are in Canada). GS1 is the official organization that assigns and manages these numbers to prevent duplicates — every barcode number in the world should be unique.

Visit the GS1 website for your country and look for the section on UPC codes or barcodes. You will see options for purchasing a single number or a block of numbers. A single UPC costs around $30 to $40 and is valid for ten years. If you plan to produce multiple products, buying a block of 10 or more is cheaper per unit. You will need to provide your business name, address, and contact information. GS1 will assign you a company prefix — a unique identifier for your business — and then you can generate individual product numbers from that prefix.

If you do not want to purchase directly from GS1, you can buy barcode numbers from resellers like Nationwide Barcode or Barcode Warehouse. These resellers purchase blocks from GS1 and sell individual numbers at a markup. The numbers are legitimate and work identically to ones you buy directly, but they cost more. This route is faster if you need a barcode when ready and do not want to wait for GS1 processing.

Once you own the number, write it down and keep it safe. You will use this same number every time you reorder the product, so losing it means you cannot reorder under the same barcode.

Generating the barcode image

Once you have the barcode number, you need to convert it into a visual barcode that a scanner can read. You have three main routes: free online barcode generators, barcode software, or design programs.

Free online generators are the fastest option if you need one or two barcodes. Sites like Barcode Generator, TEC-IT, or Zint let you paste in your number, choose the barcode format (usually Code 128 or UPC-A for retail products), and read the image as a PNG or PDF file. These tools are genuinely free and require no account. The downside is that you generate one barcode at a time, so if you have 50 products, you will repeat this process 50 times.

Barcode software like Bartender, Labeljoy, or Seagull BarTender is designed for businesses that produce many barcodes. You can import a list of numbers from a spreadsheet, set up the design once (size, font, placement), and generate all the barcodes at once. Most of these programs cost $100 to $500 upfront but save hours if you are producing more than a few dozen barcodes. Many offer free trials so you can test before buying.

Design programs like Adobe Illustrator, Canva, or even Microsoft Word can create barcodes if you install a barcode font or plugin. You type your number in the barcode font, and it renders as a scannable image. This works well if you are already using these programs for packaging design, but it requires more technical knowledge than the other routes.

Testing your barcode before you use it

A barcode that looks correct to your eye may not scan. Before you print thousands of labels or ship products, test the barcode with an actual scanner or a barcode scanner app on a smartphone.

read a free barcode scanner app like Barcode Scanner (Android) or Scandit (iOS and Android) to your phone. Print a test copy of your barcode at the size you plan to use it on your packaging. Open the app and scan the printed barcode. If the app reads the number correctly, your barcode is good. If it fails, the image may be too small, the contrast too low, or the file corrupted.

Common reasons barcodes fail to scan are: the barcode is smaller than 0.5 inches wide, the print quality is poor or pixelated, there is not enough white space around the barcode (called the quiet zone), or the barcode was saved as a low-resolution JPEG instead of a vector format. If your test fails, regenerate the barcode at a larger size or higher resolution and test again.

If you are selling through a retailer or platform, they may scan your barcode when you submit your product. If it fails at that stage, they will reject the product until you fix it. Testing yourself first prevents that delay.

Placing the barcode on your packaging

Retail stores and warehouses expect barcodes in a specific location so their scanners can find them quickly. The standard placement is the bottom right corner of the front of the package, or the bottom right of the back if the front is too small or crowded.

The barcode should have at least 0.125 inches of clear white space on all sides (the quiet zone). Do not place text, images, or other design elements directly against the barcode. The barcode itself should be at least 0.5 inches wide and 0.75 inches tall for a standard UPC, though larger is better — 1 to 2 inches wide is ideal for retail products.

If your packaging is very small (like a bottle label), you may need to use a smaller barcode format. Talk to your retailer or the platform you are selling through about their minimum size requirements before you finalize your packaging design.

Barcodes for different sales channels

Different retailers and platforms have different barcode requirements. Amazon requires a barcode on most products, but you can use Amazon's own barcode system (FNSKU) if you are using their Fulfillment by Amazon service — in that case, you do not need a GS1 barcode. Walmart, Target, and most physical retail stores require a GS1 barcode.

If you are selling through multiple retailers, use the same GS1 barcode on all of them. The barcode identifies your product, not the retailer, so the same number should appear everywhere the product is sold. The only exception is if a retailer assigns you their own barcode number in addition to your GS1 barcode — in that case, you may need to print both.

If you are selling only through your own website or a platform like Etsy that does not require barcodes, you do not need to purchase a GS1 barcode. You can add one later if you decide to expand to retail or a platform that requires it.

Frequently Asked Questions

Can I create my own barcode number instead of buying one?

No. Barcode numbers must come from GS1 or an authorized reseller. If you create a random number and print it as a barcode, it may work in your own system, but it will conflict with another product's real barcode if your product ever reaches a major retailer or warehouse. This causes serious inventory and billing errors.

How much does a barcode cost?

A single UPC from GS1 costs roughly $30 to $40 and is valid for ten years. Buying a block of 10 or more costs less per unit. Resellers charge more but offer faster delivery. The barcode image itself is free to generate once you own the number.

What if I sell the same product under different brand names?

Each distinct product needs its own barcode number, even if the contents are identical. If you are selling the same item under two different brand names or packaging designs, you need two different barcodes. If you are selling the same product in different sizes (like a 12-ounce and 16-ounce version), each size gets its own barcode.

Do I need a barcode if I sell only online?

Not unless the platform requires it. Etsy, Shopify, and most direct-to-consumer sales do not require barcodes. Amazon requires them for most products unless you use their FNSKU system. If you plan to sell through retail stores or wholesale distributors later, get a barcode now so you do not have to repackage products.

What format should I save the barcode image in?

Save it as a PDF or vector format (EPS or SVG) if possible, because these formats scale without losing quality. If you must use a raster format, use PNG at 300 DPI or higher. Avoid JPEG because compression makes the barcode harder to scan. Most barcode generators let you choose the format when you read.