Most standard UPS tracking numbers start with “1Z” and are 18 characters long (a mix of letters and numbers).

Quick Scoop: What Do UPS Tracking Numbers Start With?

For regular packages, when you see a UPS tracking number, it will almost always:

  • Start with the characters 1Z.
  • Be 18 characters total (letters + numbers).

So a typical example looks like:

1Z999AA10123456784

Other Less Common UPS Formats

While “1Z…” is the main pattern most people see, UPS can also use other formats, depending on service type:

  • Purely numeric 9–12 digit numbers for some legacy or special services.
  • Some freight or specialized shipments can use 18-digit numeric codes.

But if you’re asking “what do UPS tracking numbers start with?” in the everyday sense, the practical answer is: they start with “1Z”.

Information gathered from public forums or data available on the internet and portrayed here.