You may have heard of FedEx Ground Economy, previously known as FedEx SmartPost. This is a postal service that is shipped by FedEx but gets passed to USPS for delivery, and if you have chosen to use it, you’re probably wondering how the FedEx to USPS tracking system works.If you’re looking to track a FedEx parcel after it has been transferred into the USPS system, you can still use the tracking number provided by FedEx, but you need to add “92” to the start of the number. This changes it from a 20 digit number to a 22 digit number, making it compatible with the USPS tracking system.Why Would My FedEx Mail Be Passed To USPS?Your FedEx mail will only be passed to USPS if you have used a service such as FedEx Ground Economy. This service makes use of USPS’s extensive mail network to offer cheap and reliable postage options to businesses.The service takes away some of the things that FedEx usually offers, but it’s a very cheap option, and many businesses use it. It’s suitable for inexpensi...