<P> Tracking numbers are numbers given to packages when they are shipped . Tracking numbers are useful for knowing the location of time sensitive deliveries . In the United States, some of the companies and organizations that use tracking numbers are UPS, FedEx, and the United States Postal Service . Most Postal Services use the international S10 (UPU standard), including the United States Postal Service and most European Postal Services . </P> <P> FedEx Ground and Express tracking numbers can be between 12 and 14 digits . Prior to January 2013, Ground tracking numbers were up to 15 digits and Express numbers were up to 12 digits . </P> <P> A UPS tracking number, for domestic packages within the United States, will usually start with "1Z" followed by a 6 character shipper number (numbers and letters), a 2 digit service level indicator, and finally 8 digits identifying the package, for a total of 18 characters . </P> <P> DHL Express supports the carrier - independent ISO standard 15459 - 1 for the identification of single packages . Such identifiers consist of upper - case characters and numerals, and they can be up to 35 digits long . Companies that already use this standard do not require an additional identifier to track their pieces when shipping with DHL Express . In addition, DHL Express uses numeric identifiers of exactly ten digits to track transport orders (i.e. an order to transport a shipment consisting of one or more pieces from A to B). Customers can use both codes for tracking purposes . </P>

How long is a tracking number for ups