What is Shipping Label?

A shipping label is the standardized document attached to a package that provides carriers with the essential information needed to route, transport, and deliver the shipment. Every shipping label includes the sender’s return address, the recipient’s delivery address, a carrier-specific tracking barcode (or QR code), the shipping service level (ground, express, overnight), package weight, and any special handling instructions. The label is the physical link between the digital order in your system and the physical package moving through the carrier’s network. Without an accurate, scannable shipping label, a package cannot enter the carrier’s tracking and routing infrastructure.

Why It Matters

Shipping label accuracy and generation speed directly affect fulfillment efficiency and delivery reliability. Errors on shipping labels—wrong ZIP codes, misspelled street names, missing apartment numbers, or incorrect service levels—cause delivery failures, returned packages, and additional charges from carriers for address corrections. Each failed delivery attempt costs $5–15 in carrier fees and redelivery charges, plus the customer service time required to resolve the issue. At scale, label errors become a significant operational cost.

Label generation speed also impacts fulfillment throughput. In high-volume operations, printing labels is a bottleneck if the process requires manual data entry, switching between carrier websites, or copying order details between systems. Integrated label generation—where labels are produced directly from order data with a single click or automatically in batch—eliminates this bottleneck and enables warehouse teams to process more orders per hour. The difference between manual and automated label generation can be the difference between shipping 50 and 500 orders per hour.

How It Works

Shipping label creation involves data assembly, carrier communication, and physical production:

• Address Validation: Before generating a label, the system validates the recipient’s address against carrier databases (USPS Address Verification, UPS Address Validation, etc.). This step catches errors, standardizes formatting, and confirms deliverability. Addresses flagged as undeliverable are routed for manual review before a label is printed.
• Carrier and Service Selection: The system determines which carrier and service level to use based on delivery speed requirements, package dimensions and weight, destination zone, and cost. This can be automated through business rules or manual through operator selection. Rate shopping across carriers at this stage ensures cost optimization.
• Label Data Assembly: The system compiles all required label fields: origin address, destination address, package weight and dimensions, service level, tracking number (assigned by the carrier’s API), and any special services (signature required, insurance, hazmat markings). International shipments require additional customs documentation integrated into or accompanying the label.
• Printing and Application: Labels are printed on thermal printers (for high-volume operations using 4”×6” thermal labels) or standard laser/inkjet printers (for lower-volume operations). The label is affixed to the package’s largest flat surface, with the barcode unobstructed for scanning. Packing slips or customs forms are included inside the package as needed.

How Nventory Helps

Nventory streamlines shipping label generation by integrating directly with major carriers through a unified API. Labels are generated from order data with a single click—no manual data entry, no switching between carrier websites, and no copy-paste errors. Built-in address validation catches errors before labels are printed, reducing failed deliveries. Batch label printing lets warehouse teams generate hundreds of labels at once, and rate shopping ensures every label uses the most cost-effective carrier for that specific shipment. The result is faster fulfillment, fewer errors, and lower shipping costs.