How To Print, Encode, And Place Purchase Order Number (PO) On Shipping Packaging

Purchase Order Number (PO) is an identifier printed or encoded on shipping packaging for the supply-chain purpose described by 'Purchase Order Number (PO)'. Implementing the right print, encode, and placement standards ensures receiving speed, scan reliability, and fewer exceptions.

Labeling specifications should be practical: readable at a distance, compatible with barcode scanners used at docks, durable through handling, and consistent across suppliers. This article covers barcode types, placement rules, data structure, and validation steps for PO labeling in fulfillment operations.

Choosing The Right Barcode And Data Structure

For POs, Code 128 and GS1-128 are common. Code 128 works for variable-length alphanumeric POs; GS1-128 adds structured Application Identifiers (AIs) to combine PO with other data (batch, quantity, serials) in one scan. Use GS1-128 when trading partners or regulatory frameworks require standardized AIs; use Code 128 for simpler internal flows.

Label Content And Format

• Human-readable PO: Print the exact PO string in plain text near the barcode for visual confirmation and manual entry if scanning fails.
• Barcode encoding: Encode the PO in a Code 128 or GS1-128 symbol sized to meet scanner/read rates — commonly 50–100 mm wide depending on density.
• Complementary fields: Optionally include SKU, quantity, pack type, and carrier tracking in separate fields or embedded via GS1 AIs.

Placement And Durability Rules

Placement should minimize read obstructions. Place a PO barcode on at least two orthogonal sides of master cartons or on both the front and the top of a pallet so forklift operators can scan without rotating the load. Choose label materials resistant to moisture, abrasion, and UV if shipments travel in outdoor or refrigerated environments.

Integration With EDI And ASNs

When vendors send ASNs (Advanced Ship Notices) or EDI 856 messages, the ASN should reference the PO number exactly as printed. For EDI-driven supply chains, align the PO formatting rules with the EDI transaction set — for example, ensure leading zeros or hyphens are preserved consistently to avoid mismatches during automated matching.

Verification And Quality Control

• Vendor proofing: Require label samples during supplier onboarding and perform scan tests with the same readers used at the receiving dock.
• Automated validation: Use printer-verifier hardware or handheld scanners to confirm barcode readability and data accuracy before shipment departs the vendor site.
• Receiving checks: Implement a two-scan rule at the dock: scan the PO barcode, then scan a SKU or carton ID to ensure the PO links to expected content.

Common Labeling Mistakes To Avoid

Typical errors include truncating POs on narrow labels, using low-contrast print on colored cartons, placing labels over seams or corners, and omitting human-readable PO text. Any of these issues increases manual handling time and exception rates.

Practical Example: Supplier Label Spec

Sample supplier spec: Print PO as human-readable text (font size ≥12pt) plus a Code 128 barcode that encodes the full PO string. Place a label on the top and at least one side of each master carton. If shipments are palletized, include the same PO barcode on the pallet label and in the ASN. Use weatherproof adhesive labels for refrigerated shipments.

In short, the Purchase Order Number (PO) printed or encoded on shipping packaging should be formatted, encoded, and placed to support rapid scanning, automated matching, and reliable traceability. Clear vendor specs, verification steps, and alignment with EDI/ASN data eliminate common receiving bottlenecks and reduce reconciliation work for fulfillment teams.