Printed barcode won't scan

Start by checking whether the scanner reads a value from the label. A readable barcode can still fail to find a product in your POS.

Check what happens when you scan

• If the scanner does not respond, try a printed barcode that normally works with the same scanner. Check its power, connection, and supported barcode formats before changing the label.
• If it indicates a successful scan but nothing reaches the app, check its connection and scanner mode. For an HID keyboard scanner, scan into an empty text field to see the value it sends. Shopify’s HID scanner guide explains this test and the Allow HID mode setting in POS.
• If the app receives a value but cannot find the product, skip to Check the product match.

Check the barcode format

In the label designer, select the Barcode element and check its Type. The format must accept your value and be supported and enabled on the scanner.

CODE128 can encode internal codes containing letters and numbers. For an existing UPC or EAN, choose the corresponding format and use a valid value. See Barcode Formats.

A 1D-only scanner cannot read a QR code. Check your exact scanner model before changing formats. Shopify lists the difference in its 1D and 2D scanner guide.

Give the barcode enough room

Long CODE128 values need more width to keep the bars readable. Fitting more characters into the same narrow element can make the bars and spaces too fine for your printer or scanner.

1. Open the template in the label designer and select the Barcode element.
2. Drag a side resize handle outward to make the barcode wider.
3. Move nearby text, borders, or images away from the bars. Leave blank space at both ends of a linear barcode and keep it clear of the label edges.
4. Save the template and generate a new PDF using the actual product value. Include products with longer codes when testing a template used across your catalog.

The blank space is called the quiet zone. Its required size depends on the barcode format; see Zebra’s quiet-zone guidance. If the label cannot fit the barcode and its clear space, use a larger label and a matching template. Keep the full identifier intact.

Check the PDF and printed label

Follow Print your first labels to generate and download a small test PDF.

1. Open the PDF and check that the barcode is complete, has clear space around it, and does not overlap other elements. Correct problems visible in the PDF before printing again.
2. Match the print-dialog paper size to the PDF and use 100% / Actual size. Turn off Fit to page or other scaling that changes the label size.
3. Inspect the printed bars for fading, gaps, smudging, or bars running together. Follow your printer manufacturer’s cleaning and media instructions. For thermal printers, check darkness and speed settings; printing too dark can also make a barcode unreadable. See Zebra’s print-quality troubleshooting.
4. Print and scan a few labels with the device you will use at checkout. Change one setting at a time and compare the results.

A clear PDF helps you inspect the layout, but only testing the printed label confirms that your setup can read it. There is no universal minimum bar width for every phone, laser scanner, or imager, and 300 dpi is not a universal printing requirement. See Low-quality printing results for printer and design checks.

Check the product match

If the scanner sends a value but POS cannot find the item, search for the product by name first.

In Shopify POS, products must be available on the Point of Sale sales channel. Check the product’s status, publishing settings, and the store and location selected in POS. Product imports can delay search results after setup or a location change. See Shopify’s product search guide.

If name search works, compare the scanned value with the barcode or SKU saved on the exact variant. Check leading zeros, spaces, extra scanner characters, and duplicate values. Confirm that the template’s Link To field uses the intended BARCODE or SKU data, then generate a fresh label if the saved value has changed.

Shopify POS supports barcode and SKU lookup. Scanning into the search bar shows the main product, so you still need to choose the variant. Follow Using BarcodeMan with Shopify POS for scanner setup and checkout testing. For another POS, check its identifier fields and lookup requirements.

Still not working?

Send support the generated PDF, a photo of the printed label, label dimensions, and your scanner and printer models. Include the barcode format and expected value, and say whether the scanner gives no response, sends an unexpected value, or sends the correct value but POS cannot find the product.