USPS Tracking API
About USPS
The United States Postal Service is an independent agency of the executive branch of the United States federal government responsible for providing postal service in the United States, including its insular areas and associated states.
USPS Tracking number Instructions:
The most common tracking number format is 22 digits, or a combination of 13 alphabetic and numeric characters, usually starting with 2 alphabets, following by 9 digits, and ending by "US" (e.g. EA 999 999 999 US).
