Barcodes are central to how SKULabs handles picking, verification, receiving, and inventory management. This guide covers the most common scanning issues, printing problems, import errors, and setup questions customers ask about.
Scanning issues
"Invalid scan" when scanning a barcode
An "invalid scan" error means SKULabs received a scan but could not match it to any item, bin, or order in the system. The most common causes are:
The barcode isn't assigned to any item in SKULabs. Go to Inventory, search for the item by name or SKU, open it, and check the Barcode field. If it's blank, add the barcode and save.
The scanner is only reading part of the barcode. This usually means the scanner sensitivity or decode range is set too low, or the label is damaged. Try scanning slower, from a better angle, or with the scanner closer to the label. Some scanners need to be configured to read longer barcodes (e.g. 14-digit GTIN). See your scanner's manual for symbology settings.
The barcode has trailing spaces or special characters. Some manufacturers (especially in automotive and industrial sectors) print barcodes that include trailing whitespace. When scanned, the extra space causes a mismatch. Contact SKULabs support — we can update the item to include an additional barcode with the trailing space stripped.
You're scanning in the wrong context. A bin barcode will only work when you're in a batch picking context that expects bin scans. A product barcode won't work if the system is waiting for an order barcode. Make sure you're scanning the right type of barcode for the current screen.
Barcode scans correctly in Inventory search but gives "invalid scan" during order verification
This happens when the item is linked to multiple listings but the verification screen is looking for a specific listing barcode rather than the item barcode. It can also happen if the item has multiple barcodes and the scan matches an additional barcode that isn't the primary one recognized by the verification workflow.
Fix: Contact SKULabs support with the specific order number and item. We can check how the item's barcodes and listings are configured and adjust the verification matching.
Printed barcode labels won't scan back
If you print a barcode label from SKULabs and then can't scan it back, the issue is usually one of three things:
The label printed at too small a size. Barcode scanners need a minimum bar width to decode reliably. Increase the font/barcode size in your barcode template.
The barcode part number is printing truncated or garbled. This happens when the barcode field contains special characters (slashes, hyphens in unusual positions, Unicode) that confuse the barcode rendering engine. Contact SKULabs support with an example item SKU.
The wrong barcode symbology is being used. Some barcode types (Code 128, Code 39, QR, EAN) have different scanning requirements. Most standard USB and Bluetooth scanners support all common types, but industrial scanners may need to be configured. Check your scanner's settings.
Scanner works in other apps but not in SKULabs
If your scanner scans fine in the SocketScan app, a notepad, or other software, but doesn't work in SKULabs, the issue is usually one of the following:
The scanner is in keyboard mode but SKULabs needs a different input mode. Most USB and Bluetooth HID scanners send keystrokes — this works with SKULabs. Make sure your scanner isn't configured in a special mode (e.g. serial, SPP Bluetooth, or CDC mode).
The scanner isn't paired to the correct device or browser tab. Bluetooth scanners need to be actively connected to the device where SKULabs is open. If another app grabbed the Bluetooth connection, disconnect and reconnect.
The SKULabs input field doesn't have focus. The scan field must be the active/focused input. Click into the scan field before scanning.
IT/network restrictions. Some enterprise IT environments block scanner device connections to browser applications. If your IT department requires specific IP/port settings, contact SKULabs support — we can provide the technical details they need.
Scanner is kicking user to the dashboard mid-scan
This usually happens when a scan triggers a barcode that matches a navigation shortcut or a system command instead of an item. It can also happen if the session times out at the moment of scan.
Fix: Contact SKULabs support with the order number and the specific item being scanned when this happens. We can identify whether the barcode value is conflicting with an internal command.
Bin barcode won't scan during batch picking
If scanning a bin barcode during batch picking gives an invalid scan or no response, check the following:
The bin must be set up in SKULabs under Inventory > Locations with a barcode assigned. Go to the location and confirm it has a barcode value.
Make sure the batch type is configured to require bin scans. Go to Settings > Change batch settings and check the Bin scans setting.
Confirm the label you're scanning is the correct bin barcode (not a product label placed near the bin).
14-digit or long barcodes not scanning on Android devices
Some Android scanners (including Zebra devices) have per-symbology length limits that default to a maximum of 13 digits for EAN/GTIN codes. A 14-digit barcode will scan as invalid.
Fix: On the Zebra device, go to the DataWedge app → your profile → Barcode Input → configure the EAN-14 or GTIN-14 symbology to be enabled. Alternatively, contact your scanner vendor for the correct configuration profile.
Scanning a box barcode in the Ship window doesn't work
The Ship window's scan field is looking for an order barcode or item barcode — not a package/box barcode. Shipping box barcodes are not currently supported as a scan trigger in the Ship window.
Fix: Use the order barcode (from the packing slip or pick list) to pull up the order in the Ship window. If you need box scan support as part of your workflow, contact SKULabs support to discuss options.
Barcode label printing issues
Barcodes printing off-center or misaligned
Alignment issues are almost always caused by the barcode template or printer driver settings, not SKULabs itself.
Go to Settings > Printing > Templates, find your barcode template, and adjust the margin/padding values.
If using an Avery sheet template (e.g. 5160), make sure the label dimensions in the template match the physical label sheet exactly.
For thermal printers, recalibrate the printer using the printer's built-in calibration routine (usually a button hold sequence on startup). Misfeeds and calibration drift are common causes of offset prints.
Barcodes printing sideways or in landscape
The barcode template has its orientation set to landscape, or the printer driver is overriding the orientation.
Go to Settings > Printing > Templates and check the template CSS for a landscape orientation setting. Remove it or change it to portrait.
In your printer driver settings, confirm the paper orientation is set to portrait.
Barcode printer shows as offline in SKULabs
Even if the physical printer is powered on and connected, SKULabs can show it as offline if the SKULabs Printer Driver can't communicate with it.
Open the SKULabs Printer Driver application on the computer connected to the printer.
Check that the printer appears in the driver's printer list and shows as online.
If the printer isn't listed, reinstall the printer driver on the computer and re-add the printer in Settings > Printers in SKULabs.
If it shows online in the driver but offline in SKULabs, try refreshing the page and checking the printer connection in Settings > Printers.
Barcode printing quantity defaults to on-hand count instead of 1
When printing barcodes from the Inventory page, SKULabs defaults the quantity to the item's on-hand count. To change this, manually type "1" in the quantity field before printing. There is currently no setting to change the default — if this is important to your workflow, submit feedback via the thumbs down button.
Browser crashes when printing a large batch of barcode labels (2,000+)
Generating a very large barcode PDF in a single print job can exceed browser memory limits and cause a crash.
Fix: Print in smaller batches — 200–500 labels at a time is usually stable. If you regularly need to print very large quantities, contact SKULabs support to discuss alternative approaches.
Can't skip rows when printing on a partially used label sheet
SKULabs doesn't currently support starting a print job on a specific row/column of a sheet. To avoid wasting labels, print the exact number you need and use the next sheet fresh. If this is a frequent issue, consider switching to a roll-based thermal label printer which prints labels one at a time with no waste.
Customizing barcode label templates
Barcode label templates in SKULabs are customizable. Go to Settings > Printing > Templates and select a barcode template to edit. If you're not comfortable editing templates yourself, contact SKULabs support and we can build or modify one for you.
Commonly requested label customizations
Add bin/location to the label — Use the
##{{LOCATION}}variable in your template to show the item's warehouse location.Add the current date — Use the
##{{CURRENT_DATE}}variable. This auto-updates each time a label is printed.Show both the barcode image and the barcode number as text — Most default templates include both, but if yours doesn't, contact support to add the text element.
Add SKU to the label — Use the
##{{SKU}}variable.Custom text field — Static text can be added directly to the template HTML. For a dynamic field, contact SKULabs support.
Print barcodes on purchase orders — This requires a PO template update to add a barcode column. Contact SKULabs support with your store name.
Print barcodes on transfer orders — Contact SKULabs support — this requires a template update.
Print barcodes on pick lists — Supported via the pick list template. Contact SKULabs support to enable it.
Barcode import errors
CSV header invalid error
CSV header appears to be invalid. Accepted column names are as follow: active, name, sku, barcode, location, warehouse...
The column headers in your CSV file don't match what SKULabs expects. This is case-sensitive and must match exactly.
Fix: Make sure your CSV has the column headers exactly as shown in the error message. Download SKULabs's CSV export as a starting point to get the correct column names.
"Neither a SKU or Barcode header was found in the file"
Your import CSV is missing both the sku and barcode columns, or they're named differently.
Fix: Add a column named sku or barcode (lowercase) to your CSV. At least one of these is required for SKULabs to match rows to existing items.
"An item with barcode X may already exist. All items must have unique barcodes"
You're trying to import a barcode that's already assigned to a different item in SKULabs. Barcodes must be unique across all items.
Fix: Search for the barcode in SKULabs (Inventory > search by barcode) to see which item it's assigned to. If it's a duplicate or mistake, remove the barcode from the existing item first, then re-run the import. If two different products genuinely share the same barcode (common with repackaged goods), use the Additional Barcodes field instead of the primary barcode field.
"The following SKUs or barcodes aren't found in SKULabs"
You're importing data (inventory counts, a PO receipt, etc.) that references SKUs or barcodes that don't exist in SKULabs.
Fix: Make sure the items exist in SKULabs before importing. Export your SKULabs item list to compare SKUs/barcodes against your import file. Correct any mismatches and re-import.
Items not importing because the barcode field is blank
Some store settings in SKULabs require a barcode for items to be created or imported. If your items don't have barcodes from your sales channel, you have two options:
Enable the setting to allow items without barcodes. Go to Settings > Stores > (edit your store) > Advanced and look for the barcode requirement setting.
Generate barcodes for your items. You can auto-generate a barcode for an item that doesn't have one — see the section below.
Barcode import messed up existing items — need to undo
If you accidentally imported incorrect barcodes that overwrote existing ones, contact SKULabs support as soon as possible. We can review the import history and help restore the previous values. For future imports, always test with a small batch (5–10 items) before running a full import.
PO import requires barcode or MPN but vendor doesn't provide them
When importing a PO, SKULabs needs to match each line item to an existing item in your catalog. It uses SKU, barcode, or MPN to do this. If your vendor's PO doesn't include any of these, you can use the SKU column in the import file and map it to the item's SKULabs SKU manually.
Managing barcodes in SKULabs
How to add or update a barcode on an item
Go to Inventory and search for the item.
Click the item to open it.
Find the Barcode field and enter the barcode value.
Click Save.
How to add multiple barcodes to one item (Additional Barcodes)
If a product has multiple valid barcodes (e.g. a UPC and an EAN, or a manufacturer barcode and your internal barcode), use the Additional Barcodes field.
Open the item in Inventory.
Look for the Additional Barcodes field (below the main Barcode field).
Enter the additional barcode values. SKULabs will recognize scans of any of these barcodes for this item.
How to generate a barcode for an item that doesn't have one
If an item doesn't have a manufacturer barcode, you can have SKULabs generate a random barcode:
Open the item in Inventory.
Click the barcode field and look for a Generate option, or leave it blank and SKULabs will auto-generate one.
Save the item and then print your barcode labels for it.
How to bulk update barcodes via CSV
Go to Inventory > Export and export your items to CSV.
Edit the
barcodecolumn with the correct values.Go to Import/Export > Import Items and upload the updated CSV.
SKULabs will match rows by SKU and update the barcode field.
Important: Test your import with a small batch first. A barcode import error can affect existing items. Always keep a backup of your export before importing.
How to handle two products with the same barcode
All items in SKULabs must have unique primary barcodes. If two different products genuinely share a barcode (common with repackaged, bundled, or private-label goods), here are your options:
Assign the shared barcode as the primary barcode to one item and leave it off the other — then use a different identifier (SKU, custom label) for the second item.
Create a new internal barcode for one of the items and print new labels for that product.
Contact SKULabs support if you need guidance on the best approach for your catalog.
Barcode in SKULabs doesn't match what's in Shopify
This can happen when a listing sync runs and Shopify sends a different barcode value than what SKULabs currently has. By default, SKULabs does not overwrite the item barcode during a listing sync — it only sets the barcode when the item is first created.
If your barcodes are being managed in Shopify and you want SKULabs to stay in sync, contact SKULabs support — we can enable barcode sync for your store so Shopify barcode updates flow through to SKULabs items.
How to edit the barcode on a kit
Go to Inventory and search for the kit.
Open the kit and find the Barcode field.
Update the barcode and save.
Note: Kits can have their own barcode that is separate from the barcodes of their component items. Scanning the kit barcode during verification will verify the kit as a whole unit.
Scanner setup and recommendations
Recommended scanner types
SKULabs works with any barcode scanner that acts as a USB HID (keyboard) device or a Bluetooth HID device. Most off-the-shelf scanners work out of the box. Commonly used setups include:
USB wired scanners — plug-and-play, no configuration needed. Works on any computer running SKULabs in a browser.
Bluetooth scanners (Honeywell, Zebra, SocketScan) — pair via Bluetooth to a computer, tablet, or iPad. Make sure the scanner is in HID mode, not SPP/serial mode.
Wireless USB dongle scanners — plug the USB receiver into the computer and the scanner connects wirelessly. Works the same as wired.
Android mobile devices with built-in scanners (Zebra TC52, TC57) — use the SKULabs Android app or mobile browser. Configure the device's DataWedge profile to send scan output as keystrokes.
Can I use my phone as a barcode scanner? The SKULabs mobile app supports camera-based scanning on iOS and Android. However, camera scanning is slower than a dedicated hardware scanner and not recommended for high-volume warehouses. For occasional use, it works fine.
Using a barcode scanner with an iPad
Pair a Bluetooth scanner (Bluetooth HID mode) to the iPad via iOS Settings > Bluetooth. Once paired, open SKULabs in Safari and the scanner will send input to whatever field is focused on screen. The SocketScan S700 and Honeywell Voyager 1602g are popular choices for iPad use.
Amazon Transparency barcode scanning
Amazon Transparency barcodes are 2D DataMatrix codes that need to be scanned and submitted to Amazon when shipping eligible items. In SKULabs, you can scan Transparency codes during the ship workflow:
Open the order and start the ship process.
When prompted to scan items, use a 2D scanner (your scanner must support DataMatrix — most 2D imagers do).
Scan the Transparency code instead of the IMEI or product barcode.
The code is captured and associated with the shipment.
Contact SKULabs support if you need help configuring your Transparency scan workflow for Amazon Buy Shipping.
Frequently asked questions
Can I search open POs by barcode?
Yes. In Purchasing > Purchase Orders, use the search bar to search by barcode or SKU across open POs. You can also scan directly into the search field if a scanner is connected.
Can I print barcodes during a cycle count?
You can scan items by barcode during a cycle count — scan the product barcode and then enter the counted quantity. You can also enter items by SKU if you don't have a scanner available. See Inventory > Cycle Count.
Can I scan a kit barcode instead of scanning each component?
Yes — if a kit has its own barcode assigned, scanning the kit barcode during batch verification will verify the entire kit at once. Make sure the kit has a barcode assigned (see How to edit the barcode on a kit above) and that your batch type is set to verify at the kit level.
Why does my item have a barcode from Shopify that I don't recognize?
When SKULabs imports listings from Shopify, it creates items using the barcode field from the Shopify variant. If Shopify had auto-generated or unexpected barcodes, those will appear in SKULabs. You can update them by editing the item in Inventory or running a CSV import with the correct values.
How do I delete an incorrectly imported barcode from an item?
Open the item in Inventory, clear the Barcode field, and save. For additional barcodes, open the item, find the Additional Barcodes section, and remove the incorrect entry.
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