Understanding Tracking Numbers

# Understanding Tracking Numbers Tracking numbers come in various formats depending on the carrier. Learning to identify these formats can help you track packages more effectively. ## Common Tracking Number Formats ### USPS - **Format**: 9400 1000 0000 0000 0000 00 - **Length**: 22 digits - **Example**: 9400109699938838838838 ### UPS - **Format**: 1Z XXX XXX XX XXXX XXX X - **Length**: 18 characters - **Example**: 1Z999AA1234567890 ### FedEx - **Format**: Various (12-14 digits) - **Example**: 1234567890123 ### DHL - **Format**: 10-11 digits - **Example**: 1234567890 ## Auto-Detection ShipResolve automatically detects your carrier based on the tracking number format, so you don't need to worry about selecting the right carrier manually. ## Invalid Tracking Numbers If your tracking number doesn't work: - Check for typos - Ensure all characters are included - Wait 24 hours for new shipments - Contact the sender for verification