Barcode Labels for Warehouses

A warehouse without barcodes relies on operators remembering where things are — which works until it does not. A barcoded warehouse has a single source of truth for every item location, updated in real time by scanning. Setting up a barcode labelling system is less complex than most operators expect, and the return on investment in picking accuracy alone typically pays for the label printing cost within weeks.

The Three Levels of Warehouse Labelling

Effective warehouse labelling works at three distinct levels, each with different label requirements:

Level 1 — Location labels identify where in the building an item is stored: aisle, bay, rack, level, and bin. These labels stay fixed on the infrastructure. They are read by operators navigating to a pick location or by receiving staff putting away stock.

Level 2 — Item labels identify what is stored: SKU, product name, lot number, quantity. These labels move with the item — printed when stock is received and removed at the point of use or shipment.

Level 3 — Pallet or carton labels identify a unit load: a pallet, a shipping carton, or a tote. These may carry GS1-128 application identifiers (SSCC, GTIN, lot, expiry) for supply chain traceability.

Location Code Naming Conventions

A consistent location code scheme is the foundation of a working warehouse barcode system. A common convention is aisle-bay-level-position (ABLP):

Zero-pad all numbers to a fixed width (01, not 1) so that codes sort correctly and have consistent barcode widths. Keep codes short — 10–16 characters maximum — to produce compact Code 128 barcodes. Avoid spaces and characters that transmit inconsistently from scanners.

Define the scheme before printing a single label. Changing the convention after labels are deployed means reprinting and reprogramming the WMS simultaneously, which is expensive. Document the convention and enforce it when new zones are added.

Barcode Type for Warehouse Labels

Code 128 is the right choice for virtually all warehouse labels. It handles alphanumeric location codes, lot numbers, and serial numbers in a compact format readable by every warehouse scanner in production. If your location codes are all numeric, Code 128 Subset C doubles the data density — useful for wide-range locations with long numeric identifiers.

QR codes are appropriate for asset tracking or item labels intended to be scanned by smartphones — for example, maintenance logs for equipment accessed in the field. For standard warehouse operations with handheld or forklift-mounted scanners, stick with Code 128.

Label Sizes for Warehouse Locations

Scanning distance drives label size. Use the print size guide to calculate the right barcode dimensions for your environment:

• Hand-scanning at 0.5–1 m: 3″ × 1″ label, Code 128 at 8–12 mm bar height
• Forklift-mounted scanner at 2–4 m: 4″ × 2″ label, Code 128 at 25+ mm bar height
• Overhead aisle signs at 5–10 m: 6″ × 4″ or larger, Code 128 at 50+ mm bar height

Label Durability in Warehouse Environments

Standard paper labels deteriorate quickly in a working warehouse. Foot traffic, forklift operations, humidity, condensation, chemical splashes, and direct sunlight can destroy a paper label in weeks. For most ambient warehouses, laminated polyester (BOPP) labels on an appropriate adhesive last 3–5 years. For cold storage (under 4°C), use cryo-grade polyester with low-temperature acrylic adhesive. For freezer storage (below -18°C), use polypropylene with a cryo-grade adhesive rated to -40°C.

Label holders are an alternative to adhesive labels for rack uprights: a clear plastic channel holds a paper card at the correct position and protects it from physical contact. Label holders are easier to update (slide out the card, replace it) but require installing hardware on the racking. They are common in pharmaceutical and food warehouses where product locations change frequently.

WMS Integration

The barcode system only pays off if it is connected to a warehouse management system (WMS) or at minimum a spreadsheet that tracks item-to-location mappings. When a scanner reads a location barcode, the WMS records the movement. Without this connection, you have barcodes but no systematic benefit. Even a simple spreadsheet with location codes, SKUs, and quantities is better than no record — the scan tells you the location code, and you look up the code in the spreadsheet.

Frequently Asked Questions