USPS
USPS (United States Postal Service) is United States's national postal service provider, delivering registered or express mail domestically and internationally.
Track Your USPS Package
USPS Tracking Number Format
Track your USPS shipments by entering your tracking number in the format shown below:
9400 1000 0000 0000 0000 00
USPS tracking numbers typically have 20-22 digits, often starting with "94".