What is a tracking number? Formats explained
A tracking number is the unique ID a carrier assigns to your parcel so every scan can be tied back to it. The format often reveals which carrier it belongs to — here's how to read it.
What a tracking number is
It's a unique code — usually 10 to 35 characters of letters and digits — created when the shipping label is printed. Enter it into a tracker and you get that parcel's live status and history.
Common formats by carrier
UPS numbers start with '1Z' followed by 16 characters. USPS numbers are usually 20–22 digits starting with 92/93/94. FedEx numbers are 12 or 15 digits. DHL Express is 10 digits. International postal items use the UPU format: two letters, nine digits, then a country code like CN, US or GB (e.g. LX123456789CN).
How to tell which carrier a number belongs to
You can match the prefix and length to the carrier, but the fastest way is to paste it into a universal tracker — ParcelTrack detects the carrier from the format automatically, so you don't have to guess.
Track your package now
Paste any tracking number — ParcelTrack detects the carrier and shows the live status.
FAQ
How do I know which carrier my tracking number is for?
The prefix and length are the clue: 1Z is UPS, 92/93/94 is USPS, a two-letter + nine-digit + country-code number is an international postal item. A universal tracker detects the carrier for you automatically.
Can two parcels have the same tracking number?
Not at the same time within one carrier — numbers are unique per carrier. Numbers can be reused long after delivery, and different carriers can coincidentally share a format, which is why carrier detection matters.
More guides
- How to track a package without a tracking number
- Package not moving? Why tracking stalls and what to do
- How long does customs clearance take?
- What does 'In Transit' mean in package tracking?
- USPS tracking not updating: causes and fixes
- How to track a package: the complete guide
- How does package tracking work?