Resources > Glossary of U.S. Postal Units
Post Office Classifications
[Independent] Post Office
A 'regular' post office, with its own Postmaster, also known as a main post office, or an associate office -- because it is an associate of its regional Processing & Distribution operation.
Nashville, Tennessee: South Station post office
A subordinate postal facility under the administration of a local Post Office and Postmaster, located within the corporate [or postal delivery] limits of the municipality for which the main post office is named.
Roanoke, Virginia: Hollins Branch post office
This branch of the Roanoke, Virginia Post Office lies in the town of Hollins.
A subordinate postal facility under the administration of a local Post Office and Postmaster, located beyond the corporate limits of the municipality for which the main post office is named.
  • The differentiation between station and branch is not always strictly adhered to.
  • Stations and branches can be either classified or contract.
Classified, or 'regular', operations are staffed by USPS employees.

Contract offices are operated under a contract with a private entity and staffed by non-USPS personnel, typically as part of another business. Such units provide only retail services; they do not conduct delivery or other postal operations.

→ In many postal listings, including the PMCC's Post Office Directory, a classified station is commonly abbreviated Sx; classified branch Bx; contract station S and contract branch B.
Contract Postal Unit (CPU)
Express Lube and Car Wash CPU
The Express Lube and Car Wash CPU is a contract station in Brunswick, GA.
The term CPU encompasses each of the terms: contract station; contract branch; and Community Post Office (CPO; see below).
Community Post Office (CPO)
CPO does not stand for Contract Post Office! A CPO is a form / subset of CPU, generally in a rural area, which has replaced a closed independent post office. CPOs represent the only postal retail operations in their communities. The term CPO replaced those of Rural Station and Rural Branch in the 1970s.

→ All CPOs are CPUs; not all CPUs are CPOs.
Village Post Office (VPO)
A term for a new category of limited postal outlet; like CPOs, they are generally a replacement for a closed rural post office. However, VPOs are limited as to the services they provide: they sell stamps and prepaid Flat-Rate packaging, but cannot weigh packages, certify letters, or provide any other such common postal services. The first VPO opened in August 2011 in Malone, Washington. VPOs do not possess their own postmarks.

Distinct Mail Handling Operations
Carrier Annex
A form of classified station or branch which houses mail carriers but no retail operations. One might include customer package pick-up windows, but are otherwise generally closed to the public. Analogous terms include Delivery Distribution Center (DDC); Parcel Post Annex; and Detached Carrier Unit (DCU).

Connecticut's Guilford/Madison Carrier Annex
The Guilford/Madison Carrier Annex in Connecticut serves both towns.
Processing & Distribution Center / Facility (P&DC / P&DF)
A regional mail processing plant. Processing refers to outgoing mail, gathering of mail sent from post offices across the region, cancelling of stamps, sorting according to destination and dispatch; Distribution refers to incoming mail, receiving of mail from other areas, and distributing it to the local delivery offices in the region.

Philadelphia P&DC
Philadelphia's $272 million, 910,000-square-foot P&DC was 'activated' in 2006.

Generally, the primary distinction between a P&DC and P&DF is that a P&DC is larger.

Administrative Units
USPS Headquarters at L'Enfant Plaza
USPS Headquarters at L'Enfant Plaza
USPS Headquarters (L'Enfant Plaza)
This is the administrative heart of USPS, located at 475 L'Enfant Plaza, SW in Washington, DC. However, many of the management functions are done at lower levels.
The country is divided into seven Areas (Northeast, Eastern, Capital Metro, Southern, Great Lakes, Western, Pacific), each further divided into about ten Districts. According to the USPS Office of the Inspector General, "area offices ensure headquarters directives are implemented."
This level of management is responsible for most day-to-day management duties for local post offices, including "customer service activities other than processing and distribution" (OIG). There are currently 67 Districts.

Photos are from the Evan Kalish collection.