Understanding the parts of an address helps with data processing, validation, and standardization. US addresses follow a specific structure with defined components.
US Address Structure
A typical US address consists of: Street Number + Pre-directional (N, S, E, W) + Street Name + Street Type (St, Ave, Blvd) + Post-directional + Unit Designator (Apt, Suite), followed by City, State, and ZIP Code. ZIP+4 adds four additional digits for more precise delivery.
Street Types and Abbreviations
USPS defines standard abbreviations: Street (ST), Avenue (AVE), Boulevard (BLVD), Drive (DR), Road (RD), Lane (LN), Court (CT), Circle (CIR), Place (PL), Way (WAY), Highway (HWY). Using standard abbreviations improves parsing and deliverability.
Directionals and Unit Designators
Pre-directionals come before the street name (N Main St, E 42nd St). Post-directionals come after (Pennsylvania Ave NW). Unit designators identify specific units: Apt, Apartment, Unit, Ste, Suite, #, Floor, Fl, Building, Bldg, Room, Rm.
Special Address Types
PO Boxes follow different rules: PO Box 12345, City, State ZIP. Variations include P.O. Box and POB. Rural Routes (RR 1 Box 123) were historical addressing for rural areas but most have been converted to 911-style addresses with street names and numbers.