Postal ID is an identification card issued by the United States Postal Service (USPS) to its employees. It is used to verify the identity of USPS employees and to provide access to certain USPS facilities. The term 'Postal ID' is derived from the state of IDAHO, which is abbreviated as ID in the USPS system. The Postal ID card is issued to all USPS employees and is required for access to certain USPS facilities.