UPC Barcode Generator

UPC-A: the straightforward internal option

For UPC-A, Generate Random Internal UPC uses the GS1-reserved UPC Prefix 4 company-internal RCN-12 range. The app creates the first 11 digits and calculates the 12th/check digit.

If your label has room for a full UPC-A, this is the simpler internal format to work with because the scanner reads the full 12-digit number directly.

UPC-E: useful when the label is small

For a shorter UPC-E label, this generator uses the reserved Prefix 0 Local Assigned Code (LAC) range based on UPC Company Prefixes 001000 through 007999. Only certain UPC-A values can be represented as UPC-E.

The app creates an eligible UPC-A source, calculates its check digit and shows both the short UPC-E and its expanded 12-digit internal RCN-12.

Before printing a stack of labels, scan one into your Square setup. Some scanners send the short UPC-E value while others expand it to the 12-digit value first.

Why not just make up any UPC?

Using the reserved internal ranges helps keep your convention/vendor-table catalog out of the number space used for ordinary GS1-assigned retail GTINs. It reduces the chance of accidentally using a real retail product number, but another business can still independently use the same internal number.

UPC-A: the full-size format

UPC-A uses 12 digits. For a label you are creating yourself, enter the first 11 digits here and the app calculates digit 12 as the check digit. If you already have all 12 digits, the app checks the checksum math.

A GS1 assigned retail GTIN-12 has a UPC Company Prefix and Item Reference assigned under GS1 rules. The visible digit groups under the barcode are only formatting. They are not a universal “company / category / item” breakdown.

UPC-E: the compact format

UPC-E is a shorter representation of certain UPC-A numbers, which can be handy when you are trying to fit a barcode onto a smaller tag or product.

Not every UPC-A can be compressed to UPC-E. This app supports UPC-E number system 0 and can show the expanded UPC-A equivalent. Scanner settings can affect whether Square receives the short UPC-E or the expanded value, so test your actual scanner before printing a large batch.

The check digit only checks the math

A barcode can have a perfectly correct check digit without being a GTIN assigned to you by GS1. This app checks the UPC checksum calculation; it does not look up ownership or registration. If you are sending products to outside retailers, wholesalers or marketplaces that require globally unique product identification, you will need to use properly assigned GS1 GTINs. If you get an assigned GTIN, you can still enter it here to generate the barcode image.