Shopify Barcode Labels When Products Already Have UPCs

If your products already carry manufacturer UPCs, keep them. Scan each UPC into the variant’s barcode field and set the type to UPC. Print labels only for items that have no code. In the Retail Barcode Labels app, never use Create barcodes across products that already have barcodes. Shopify warns that the app then overwrites your manually entered codes with new ones based on variant IDs.

This guide covers the Shopify barcode labels existing UPC workflow for an ecommerce business with one counter.

The overwrite warning, exactly

Shopify’s help page for the free Retail Barcode Labels app puts this caution under Barcode generation. If you create new barcodes for products with manually entered ones:

“the app overwrites the existing barcodes with new barcodes based on variant IDs.”

To keep them, Shopify says to “create new barcodes only for specific products that don’t already have barcodes assigned.”

The UPC on the box and the code in Shopify then stop matching, and every scan fails.

UPC basics for Shopify merchants

What a UPC is

UPC stands for Universal Product Code. GS1 US calls it “a series of black lines that help identify a product.” The number under the bars is a GTIN, the unique identifier that links scan data to that exact item.

GS1, the global standards organization behind the universal product code, licenses UPC barcodes. GS1 Canada calls itself “the only official provider of GS1 GTINs and UPC barcodes globally.”

How to read a UPC-A number

GS1 US describes UPC-A barcodes as “the flagship 12-digit format used predominantly by retailers throughout North America.” Its example is 6 14141 99999 6:

Company prefix. The first 6 to 10 digits identify the brand owner, assigned by GS1.
Item reference. The next digits identify the item. Every size or colour gets its own.
Check digit. The last digit confirms the number reads correctly.

GS1 US offers a free check digit calculator. Verify any code you type by hand; typing errors, not supplier UPC-A barcodes, are the usual risk.

UPC-A, UPC-E and EAN-13

GS1 US lists three retail barcode types you will meet on supplier stock:

Barcode type	Digits	Where you see it
UPC-A	12	Most North American retail products
UPC-E	6	Small items such as cosmetics and candy, where space is tight
EAN-13	13	Products from outside North America, scanned at the same registers

Shopify’s product page says UPC values “can be 8 or 12 digits” and EAN values “8 or 13 digits.” For a code that “doesn’t follow a set standard,” Shopify says to keep the type as Custom.

SKU vs UPC

A SKU (stock keeping unit) is your own internal code. Shopify says “each SKU needs to be unique,” and “You can create your own SKU format.” A SKU means nothing outside your business.

A UPC is a global code any retailer can read. Use the SKU for internal tracking and the UPC to scan and sell online. In our accounts, the cleanest stores keep both on every product variant, so inventory data matches.

Step 1: Enter the UPCs you already have

On each variant, Shopify lets you store more than one code. The product details page says “You can add up to 20 barcodes to a product or a variant.” Each barcode has a type: Custom (the default), GTIN, UPC, EAN, ISBN or ASIN. The barcode value must match that standard’s length and characters.

Set the type correctly. A UPC left as Custom still scans, but Shopify notes “Some sales channels might require a GTIN.”

One rule to respect: “The same barcode value can’t be used twice on the same product or variant.”

Use your phone or a USB scanner to enter codes fast. For many products, a bulk edit saves time: open the bulk editor and add the barcode column. You can also “import barcodes in bulk by using the product CSV.” Save after each bulk edit.

Step 2: Add second codes for repacks and vendor changes

Vendors change packaging, and distributors use different codes. Since POS v11.14 you don’t need to choose. The September 1, 2026 changelog says: “Regardless of which associated barcode is used, Shopify POS will pull up the correct variant.” Additional barcodes “must first be associated with the product variant in Shopify Admin.”

In our accounts, this fixes most “item not found” beeps on the register. Add old and new codes to the variant.

Step 3: Create a barcode only for items without one

Two options in the app

From your Shopify admin, go to Apps > Retail Barcode Labels.
Click Create barcodes.
Choose one of two options:
- Create barcodes for products without barcodes: safe when every UPC is already entered.
- Create barcodes for specific products: pick items in the Add products dialog, then Click Add.

If you are not sure every UPC is entered, select Create barcodes for specific products and pick by hand, the route Shopify points to.

What the app generates

Know what you get before you click:

“The Retail Barcode Labels app only generates Code-128 barcodes.”
Generated barcodes are 8 digits, from the last 8 digits of the variant ID. Shopify notes duplicates are rare but possible.
“The 8-digit barcodes generated by the Retail Barcode Labels app are not suitable for Google Shopping.”
“To use barcodes with third-party channels like Google, you need to purchase unique barcodes from GS1.”

Codes you generate in the free app suit in-house items: consignment pieces, house-made goods, or bulk stock bagged in the warehouse. They are wrong for anything you sell on Google or a marketplace.

Barcode generator options and their limits

The free Retail Barcode Labels app is a barcode generator for internal codes only. It is not a source of UPC barcodes, and it won’t generate a GTIN.

A free online barcode generator can draw a barcode image of any number you type. It can’t make that number a real UPC. Only GS1 licenses a company prefix, so generator software only helps once you own the GTIN.

GS1 Canada offers its own barcode generator software to prefix holders, for high-resolution barcode files. GS1 US provides Data Hub, which calculates the check digit. In our accounts, packaging printers ask for a PNG file or vector art; GS1’s tools are where it should come from.

GS1 Canada says bars should be dark, never red, because scanners use red light. Leave the blank quiet zone either side; a barcode generator that crops it makes codes that fail.

How much UPC barcodes cost

GS1 US lists its prices on its get-started page (fetched October 18, 2026, USD):

What you license	Initial fee	Annual renewal
1 GS1 US GTIN	$30	$0
Prefix for 10 items	$250	$50
Prefix for 100 items	$750	$150
Prefix for 1,000 items	$2,500	$500

GS1 Canada prices by GTIN count and annual revenue. Both offices need unique UPCs per variant: 3 sizes in 3 colours means 9 barcodes, GS1 US says.

Most single stores never buy UPC barcodes, because suppliers own the brand. You need GS1 only if you private-label products to sell to other retailers or ecommerce sites.

Step 4: Build a label template

Go to Apps > Retail Barcode Labels and click Create template.
Enter a template title.
Choose a label in the Label type section, or under Other label types.
Choose what shows in the Label preview section: price, SKU, product title.
Click Create template.

The label template decides what vital information customers see, such as price and title. Smaller label templates offer fewer options. Make one template for shelf tags and one for small items.

Supported label size options

Shopify lists the label size options the app supports. A few common ones:

Brand	Label	Size
Dymo	30252 Large	1 1/8” x 3 1/2”
Dymo	30336 Small	1” x 2 1/8”
Dymo	30332 Square	1” x 1”
Avery	5160	2.63” x 1”
Zebra	ZSB-LC6	2.25” x 1”

Shopify says custom label sizes “can’t be added”; it points to third-party apps. Price display needs a Shopify Payments supported currency, on any Shopify plan.

How to print barcode labels on Shopify

Print barcode labels from the product list

Go to Products and select products.
Click the horizontal menu icon and choose Print barcode labels under Apps.
Select your template.
In the Products section, enter how many labels each variant needs.
Check the Print job section, then click Print labels.
Optional: set Destination to Save as PDF for a test sheet.

You can also print barcode labels from inside the app. Go to Apps > Retail Barcode Labels, click Print labels, select products, and click Add.

Printer settings that work

Shopify recommends Google Chrome. Its printer settings call for 300 x 600 DPI and portrait orientation. On a Mac, use More settings, then Print using system dialog, pick the Dymo, and set Paper Size to the label.

Labels print in alphabetical order by product title. Quantities are entered by hand; there is no CSV upload. Staff need product access in the Shopify admin.

Where printing doesn’t work

Shopify says “printing labels is currently not supported by Shopify POS.” On an iPad, the app can’t print; Shopify points to the Dymo Connect iPad app instead. You also can’t print labels while receiving a transfer in POS.

Labels also don’t auto-populate from a partial receipt. For a big delivery, Shopify suggests exporting the receiving data to a spreadsheet to print labels in bulk. In our accounts, the buyer prints from the desktop admin right after receiving.

Can I print my own barcode labels?

Yes. Shopify stores can print their own barcode labels with the free Retail Barcode Labels app and a supported label printer. Print labels for manufacturer UPCs you entered, or for internal codes the app can generate. Labels print from the Shopify admin on desktop.

What you can’t do is invent a valid UPC. Print your own retail barcode labels freely; buy UPC barcodes only from GS1.

Worked example: a gift store with mixed stock

A gift store sells 400 variants in store and through its ecommerce site. Most arrive from a distributor warehouse with UPC barcodes; 30 are house-made candles with no code.

The buyer exports product data and finds 120 variants with an empty barcode field.
Staff scan the UPCs from the boxes into 90 of them, set as type UPC, in one bulk edit.
The 30 candles need internal codes, so the buyer uses the free barcode generator: Create barcodes for specific products.
The buyer prints shelf labels for the candles only, on Dymo 30336 stock.
Manufacturer UPCs on the other stock stay untouched, and every box still scans.

The candles get 8-digit Code-128 codes. They work at the register and in inventory counts, but the store doesn’t sell them on Google. If it starts to, it needs unique UPCs from GS1 first.

Troubleshooting barcode labels

Problem	Likely cause	Fix
Register beeps “item not found”	UPC not entered, or packaging changed	Add the new code to the variant
Scan rings the wrong item	Two variants share a barcode value	Fix the duplicate in the Shopify admin
No price on the label preview	Store currency not supported by Shopify Payments	Print labels without price, or use another app
Barcode cut off on the label	Wrong paper size or print resolution	Verify paper size and 300 x 600 DPI
Odd characters on labels	Special characters in the product title	Retype the title, per Shopify
Can’t print from an iPad	The free app doesn’t print there	Use the Dymo Connect iPad app

In our accounts, most barcode labels problems are bad data entry. Save a test PDF and verify one label scans before a big print run.

Why barcodes matter at count time

Duplicate barcodes break stock counts; Shopify says a shared barcode causes a scan error. Before each inventory count, sort products by barcode and fix duplicates. Clean UPCs are good inventory management, so customers online see what is on your shelf.

QR codes and the 2027 change

GS1 US describes Sunrise 2027 as “a global transition from 1D UPC barcodes to 2D barcodes, like QR codes.” It also says “it is not necessary to implement all the capabilities of 2D by that date.” For retailers, its first step is scanners that can read 2D codes.

For a single store, the action is simple. When you replace a scanner, check it reads QR codes. Keep entering the GTIN in Shopify either way.

Canada and US differences

Both countries use the same UPC-A codes, so one barcode system works on both sides of the border. Products from Europe arrive with EAN-13 codes, which Shopify stores as type EAN.

Canadian stores buy GTINs from GS1 Canada, US stores from GS1 US, each in its own currency. If a vendor switches distributors, add both codes to the variant.

When a third-party app is the right call

The free Retail Barcode Labels app covers most single stores. Shopify points to a third-party app from the Shopify App Store in four cases. These are a missing label size, an unsupported currency, special characters, or unique generated codes. Add bulk printing for big receiving days. Label apps stores pick often add custom fields, such as a vendor code, and limit access by staff role.