Trade & Shipping · Validation
UPS tracking number checker.
Check the 18-character UPS number on a label, like 1Z879E930346834440 — its format and its check digit.
What a pass means: a UPS 1Z number is 1Z, a 6-character shipper number, a 2-character service code, a 7-character package id and 1 check digit. A pass means the check digit matches — it does not confirm a shipment exists, that the number was issued, or where a package is. This tool cannot track a parcel.
Inputs
Result
Enter a tracking number and press Check.
How the UPS 1Z check digit works
A UPS tracking number starts with 1Z, then a 6-character shipper number, a 2-character service code, a 7-character package identifier and a final check digit, for example 1Z879E930346834440.
To compute the check digit, take the 15 characters after 1Z. Digits keep their value. Letters become (character code − 63) mod 10, so A=2, B=3 ... H=9, I=0, J=1 ... Z=3. Add the values in odd positions (1st, 3rd, ...) as they are and the values in even positions (2nd, 4th, ...) doubled; call the total T. The check digit is (10 − T mod 10) mod 10.
Worked example: 1Z879E930346834440. The 15 characters after 1Z are 879E93034683444, which map to 8, 7, 9, 6, 9, 3, 0, 3, 4, 6, 8, 3, 4, 4, 4 (E = 69 − 63 = 6). Odd positions add to 8+9+9+0+4+8+4+4 = 46. Even positions add to 7+6+3+3+6+3+4 = 32, doubled 64. T = 110, so the check digit is (10 − 0) mod 10 = 0, which is the last digit of the number. It passes.
UPS does not publish this rule as a standalone specification page. The rule here comes from three maintained open-source references that agree: jkeen/tracking_number_data (UPS section, mod 10 and test numbers), jbittel/drogher and storborg/packagetrack, the last two written independently.
To see where a package actually is, use UPS Tracking.
Format check — not tracking
This tool checks format and check digit only. It cannot look up a parcel, show its location or status, or confirm that the number was issued or belongs to anyone. Only UPS 1Z numbers are recognised. To track an item, use UPS Tracking. Nothing you type is transmitted, stored, or logged.