FedEx tracking numbers are 12-15 digits long and contain a combination of letters and numbers. The first two digits of the tracking number indicate the service that was used to ship the package. For example, 1Z indicates FedEx Express, 2S indicates FedEx Ground, and 3D indicates FedEx SmartPost. The next four digits of the tracking number are the FedEx facility where the package was shipped from. The last five or six digits of the tracking number are the packages unique identifier. FedEx tracking numbers can be used to track the status of a package in transit. You can enter the tracking number into the FedEx tracking website or mobile app to see where the package is and when it is expected to arrive.

In summary, FedEx tracking numbers start with a combination of letters and numbers, with the first two digits indicating the service used to ship the package.