Start with the number
A barcode image is not a product number
A barcode is a machine-readable picture of data. The digits or characters encoded in it are the value that your inventory system, retailer or marketplace uses. A generator can draw a symbol from a value you provide, calculate a check digit for supported formats, and export artwork. It cannot assign a globally unique retail identifier, register a product with GS1, or confirm that a number belongs to your business.
That distinction matters because a barcode can look correct and still be unsuitable for a sales channel. Before generating anything, ask where the product will be scanned and who controls the number. A value for your own shelf or packing bench has different requirements from a GTIN printed on packaging and submitted to a retailer.
Retail identifiers
When you need a GS1-licensed GTIN
If an independent retailer, supermarket, distributor or marketplace asks for a product identifier, use a GTIN licensed for your product and business through GS1 or an authorized national GS1 member organisation. Depending on your country and catalog size, you may license individual GTINs or obtain a company prefix from which eligible product numbers can be allocated. Follow the current allocation rules that apply to your membership.
Large retailers and marketplaces commonly check identifier records against GS1 data. Amazon generally expects a GS1-licensed GTIN for products that require a product ID, although some products may qualify for a GTIN exemption under Amazon’s current rules. Check the requirements in your Seller Central account before buying numbers or printing packaging; exemptions and category rules can change.
Do not invent a random 12- or 13-digit value for retail sale, and be cautious with inexpensive resold numbers. A valid check digit only confirms that the arithmetic is consistent. It does not prove that the identifier is licensed to you or assigned to that product. The GS1 GTIN overview explains the role of the identifier, and your local GS1 organisation can explain licensing for your location.
Internal use
When an internal barcode is enough
If a code is scanned only by you or your staff, you can usually create an internal SKU or asset number under your own naming rules. Code 128 is useful for mixed letters and digits; a QR code can hold a URL or plain text. Use a number range reserved for internal use in your system, document the format, and avoid presenting it as a GS1-licensed retail GTIN.
Internal barcodes work well for storage bins, work orders, samples, handmade inventory, picking slips and stock that never enters a retailer’s product database. An Etsy seller can use a SKU barcode for organizing variants and packing orders without a GTIN simply because a barcode is present. Shopify stores can likewise use SKUs for internal inventory, while sales channels may separately ask for a globally unique product identifier.
Choose a symbol
Pick the format your scanner expects
For retail products outside North America, EAN-13 is common; UPC-A is widely used in the United States and Canada. Both are linear symbols for GTINs, and both include a check digit. A book’s ISBN-13 is encoded as an EAN-13 Bookland symbol. For internal labels containing letters, Code 128 is a practical choice. Do not select a format by appearance alone: confirm the exact data format requested by the receiving software or retailer.
These tools can help with the artwork after you have the right value: create an EAN-13 barcode, make a UPC-A barcode, use the check digit calculator to verify arithmetic, or prepare a bulk barcode sheet from a list. This site generates codes locally in your browser; it does not issue, license or register product numbers.
A practical workflow
Get from product to printable barcode
- Confirm the destination. Ask your retailer, marketplace, distributor or internal system which identifier and barcode format it accepts. Check whether the product requires a GS1-licensed GTIN or has an exemption.
- Obtain or assign the value. License the appropriate GTIN through GS1 for retail use. For internal stock control, create a unique SKU according to your own documented scheme. Keep product variants distinct when they are sold separately.
- Validate the value. Preserve leading zeros and verify the check digit. A check digit calculator can catch common typing errors, but it cannot validate ownership or registry status.
- Generate the symbol. Choose the format the destination requires, enter the value, and inspect the human-readable text and preview. Keep the quiet zones and do not crop the bars.
- Print and test. Use the required physical size and print at 100% or Actual size. Scan a sample with the equipment or application that will be used in practice before printing the full run.
For printed packaging, vector artwork such as SVG or PDF helps keep edges crisp when the designer places it. For labels, check the printer’s settings and label stock. A successful preview is not a print-quality certification, so test a physical sample and confirm the number against the source record.
By sales channel
Amazon, shops, Etsy and Shopify
Amazon may require a product ID such as a GTIN for a new listing, or may offer an exemption for eligible products. Follow the current product-category guidance in Seller Central; do not assume that a generated symbol or a valid check digit satisfies the requirement. If the listing asks for a GTIN, use one licensed to your product and verify the listing data before applying the label.
Traditional retailers and distributors set their own onboarding and print specifications, often based on GS1 standards. Ask for the accepted GTIN type, minimum symbol size, placement rules and any verification requirements. A retailer’s specification takes precedence over a generic online example.
Etsy does not generally require a barcode for handmade listings, so a short internal SKU can be enough for your own bins and packing workflow. On Shopify, distinguish the SKU field from the Barcode or product identifier field. An internal code can help your staff, while a connected marketplace or shopping feed may expect a registered GTIN.
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Questions
Frequently asked questions
Do I need a GS1 barcode to sell a product?
For retail distribution and many marketplace listings, you will generally need a GTIN licensed through GS1 or an accepted exemption. For internal inventory only, a unique SKU barcode may be enough. Confirm requirements with the sales channel.
Can I make a barcode without buying a number?
Yes, for internal use. You can encode your own SKU or asset value. A generated image does not grant ownership of a retail GTIN, and the tool does not register numbers with GS1.
Does Amazon require a GS1-licensed GTIN?
Amazon generally requires a valid product ID for products that need one, and GS1 licensing is the reliable route for a GTIN. Some products may qualify for a GTIN exemption under current Amazon rules, so check Seller Central for your category.
Can Etsy or Shopify use an internal SKU barcode?
An internal SKU barcode can support your own inventory and fulfillment workflow. Etsy listings do not generally require a barcode. Shopify’s SKU and product barcode fields have different purposes, and connected sales channels may require a GS1-licensed GTIN.
Does this generator register my barcode number?
No. It creates a barcode symbol from the value you enter and can calculate supported check digits. It does not assign identifiers, register products or query the GS1 registry.