Postal Letter

How are package tracking numbers for FedEx and UPS assigned?

There are patterns like how numbers increase by 7 each time a new tracking number is assigned unless the new number does not increase the second digit. Example: one number is 013840222514114 at fedex the next valid number is 013840222514121 but it skips 013840222514128 and goes to 013840222514138 My question is: what are the algorithms of assigning these numbers?

Public Comments

1. HAHAH...thats interesting....you know fedex has and arrow in the letters
2. You pretty much figured it out. Not sure about UPS (see below), but FedEx Ground tracking #s like your examples are 15 digits long, whereas current Express #s are 12 digits long. UPS has much higher volume/market share than FedEx so they have to use letters in their #s. It's kinda like the transaction code whenever you buy something and get your receipt. The # represents how many burgers have been sold so far (trillions!). If you really figure out the actual algorithm (if one indeed exists) for assigning such #s, then you've got something!