USPS Tracking Numbers Explained
Different USPS services use different tracking number formats:
| Service | Tracking Number Format | Digits |
|---|---|---|
| Priority Mail Express | EA ### ### ### US | 13 chars |
| Priority Mail | 94 or 9400... | 22 digits |
| First-Class Package | 92 or 9400... | 22 digits |
| USPS Ground Advantage | 92... | 22 digits |
| Certified Mail | 94 or 9407... | 22 digits |
| Click-N-Ship | 9400... | 22 digits |
Track any USPS package at tools.usps.com or the USPS Mobile app. You can also text your tracking number to 28777 (2USPS) to receive tracking updates by SMS.
Common Tracking Statuses Explained
- "Pre-Shipment Info Sent to USPS": Label created, package not yet dropped off or accepted by USPS
- "Accepted": USPS has physically received the package
- "In Transit": Package is moving through the USPS network
- "Out for Delivery": Carrier has the package on their delivery vehicle — expect delivery today
- "Delivered": Package was delivered. Notes where (mailbox, front door, etc.)
- "Available for Pickup": Package held at post office for you to collect
- "Delivery Attempted": Carrier tried to deliver but couldn't (no one home, access issue)
- "Alert — Insufficient Address": Address problem — package may be returned unless corrected. This is why address verification is so important.
When Tracking Stops Updating
Tracking not updating is the #1 USPS complaint. Here's what typically causes it:
- In transit between facilities: When a package is physically moving between sorting centers, there are no scan events. Updates resume at the next facility. This can take 1-3 days.
- Weekend and holiday delays: Fewer scan events occur on weekends at some facilities
- Missed scan: Scanner errors happen. The package may still be on time despite no tracking update.
- Package lost: If tracking hasn't updated in 7+ business days for domestic Priority Mail, it's time to file a missing mail search.
File a missing mail search at missingmail.usps.com. Include your tracking number, destination ZIP code (verify it with our ZIP lookup tool), and description of contents.
Proactive Tracking with Informed Delivery
Instead of checking tracking after you've shipped, use USPS Informed Delivery to get proactive daily notifications of incoming mail and packages — before they arrive.
Filing a Claim for Lost or Damaged Packages
If your package is confirmed lost or arrived damaged:
- File at usps.com/help/claims within the eligible filing window
- Priority Mail Express: file immediately after missed delivery guarantee
- Priority Mail with insurance: file 15–60 days after shipment date
- Have your tracking number, proof of value (receipt), and photos of damage (if applicable)
FAQ
Q: Why does USPS tracking say "delivered" but I didn't receive my package?
A: Check with neighbors (misdelivery is common), check around all entry points of your home, and wait 24 hours — carriers sometimes mark as delivered slightly before actual delivery. If not resolved, file a missing mail request.
Q: Can I track a First-Class letter?
A: Standard First-Class Mail (letters, postcards) does not include tracking. Only First-Class Package Service includes tracking. For letters, add Certified Mail or Delivery Confirmation as an add-on.