Tracking Number
A tracking number is a unique alphanumeric code assigned to a shipment by the carrier at the time of label creation, enabling the shipper, recipient, and any authorized party to monitor the shipment's location and status throughout its journey from origin to destination. Each scan event — carrier pickup, hub transfer, customs clearance, out-for-delivery, and final delivery — is recorded under the tracking number and made available through the carrier's tracking system.
Tracking Number Formats by Carrier
Each carrier uses a distinctive format, though most systems can automatically identify the carrier from the number format:
| Carrier | Format | Example |
|---|---|---|
| UPS | 18 characters, starts with "1Z" | 1Z999AA10123456784 |
| FedEx Express | 12 digits | 123456789012 |
| FedEx Ground | 15–22 digits | 9261290100130736401504 |
| USPS (Priority Mail) | 20–22 digits, starts with "94" or "92" | 9400111899223397694790 |
| DHL Express | 10–11 digits | 1234567890 |
| Royal Mail | 13 chars (2 letters + 8 digits + "GB") | AB123456789GB |
| PostNL International | 13 chars (UPU format) | RR123456789NL |
| China Post / ePacket | 13 chars, starts with "R" | RR123456789CN |
For international postal shipments, the first two letters indicate the type of service (R = registered, E = express, C = airmail parcel) and the last two letters indicate the country of origin.
How Tracking Events Work
Tracking data is generated by barcode or RFID scans at each physical checkpoint in the carrier's network. Key events:
- Label created / Electronic shipment information received: The label has been printed but the carrier hasn't physically received the package yet
- Origin scan / Accepted: Carrier physically received the package (at counter, via pickup, or at a drop location)
- In transit: Package is moving between facilities; intermediate hub scans
- Out for delivery: Package has been loaded onto the local delivery vehicle
- Delivered: Final delivery scan, often with GPS coordinates or photo
- Exception: Something requires attention — recipient not home, address issue, weather delay
WISMO and Tracking UX
"Where Is My Order?" (WISMO) is the most common customer service inquiry for e-commerce brands, often representing 20–40% of total support contacts. Proactive, accurate tracking communication dramatically reduces WISMO:
- Shipping confirmation email with tracking link (sent immediately at label creation)
- Out-for-delivery notification (day-of SMS or push notification)
- Delivery confirmation with photo proof
Branded tracking pages — hosted at tracking.brand.com rather than the carrier's site — keep customers within the brand experience and provide an opportunity to promote related products or loyalty programs. Tools like AfterShip, Narvar, and Wonderment enable branded tracking pages for e-commerce brands.
References
1 ParcelDetect Logistics Database, 2026.
2 Universal Postal Union (UPU) Standards.