US Postal Service federal identification code?

The U.S. Postal Service (USPS) does not have a specific federal identification code akin to those used by federal agencies. However, the USPS is an independent establishment of the executive branch of the U.S. government and is assigned a unique Employer Identification Number (EIN) for tax purposes. Additionally, USPS uses various codes for operational purposes, such as ZIP codes for mail delivery, but these are not identification codes in the federal sense.