Tracking Number Formats: How to Tell Which Carrier a Number Belongs To

Every carrier issues tracking numbers in its own pattern. Knowing the common patterns tells you roughly who is carrying a parcel. It also explains why some numbers cannot be identified from their shape alone.

Short answer

UPS numbers start with 1Z and have 18 characters. USPS numbers are usually 20 to 22 digits starting with 92, 93, 94 or 95. FedEx uses 12-digit (Express) and 15-digit (Ground) numbers. DHL Express uses 10 digits. International postal parcels use the UPU S10 format: two letters, nine digits and a two-letter country code, such as RR123456789CN. Amazon Logistics numbers start with TBA. A universal tracker like 24hTrack detects the carrier from these patterns automatically.

Common formats

  • UPS: 1Z followed by 16 letters and digits (18 characters), for example 1Z999AA10123456784.
  • USPS: 20 to 22 digits, usually starting with 92, 93, 94 or 95. Labels sometimes print 420 plus the ZIP code in front of the number.
  • FedEx: 12 digits for Express, 15 digits for Ground.
  • DHL Express: 10 digits.
  • Amazon Logistics: TBA followed by 12 digits.
  • International post (UPU S10): two letters, nine digits, two-letter country code. The country code at the end tells you the origin postal service: CN China Post, GB Royal Mail, US USPS, CA Canada Post, DE Deutsche Post.
  • YunExpress: YT followed by 16 digits.
  • Cainiao (AliExpress): often starts with LP or CN.

What the S10 prefix letters mean

In UPU S10 numbers the first letter usually indicates the service: R is registered mail, E is EMS express, C is parcel post and L is tracked packet. So RR…CN is a registered China Post item, and LX…CN is a tracked packet (ePacket).

Why some numbers are ambiguous

Many regional carriers and Chinese logistics companies use plain numbers of the same length, so a 12- or 14-digit number can belong to several companies. A number can also be re-labelled when the parcel is handed to a local carrier in the destination country.

When the shape is ambiguous, 24hTrack checks the carriers that could own the number rather than guessing, so you see the carrier that actually has the parcel.

Frequently Asked Questions

How do I know which carrier my tracking number belongs to?

Match the pattern: 1Z means UPS, 22 digits starting with 9 usually means USPS, 12 or 15 digits often means FedEx, and two letters plus nine digits plus a country code is an international postal number. Or paste it into 24hTrack, which detects the carrier automatically.

What does CN at the end of a tracking number mean?

The parcel was posted with China Post under the international UPU S10 format. It is usually handed to the destination postal service, such as USPS, for final delivery.

Why did my tracking number change?

Cross-border parcels are often handed to a local carrier that issues its own number. The original number usually keeps working, and the new one appears in the scan history.

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