This guide provides a comprehensive overview of United States address formatting, postal code structures, and localization practices. It includes information on postal services, languages, time zones, and address validation standards across United States of America.
Address Format
Structure for standardized United States postal addresses.
- Organization
- PremisesNumber, ThoroughfarePreDirection, Thoroughfare, ThoroughfarePostDirection, SubPremisesType, SubPremisesNumber
- Locality, AdministrativeArea, PostalCode
- Country
Address Verification Data
United States postal addresses verification data.
| Available: | Yes |
| Does the country use Postal Codes: | Yes |
| PO Box Indicator: | PO Box, PMB, RR, GENERAL DELIVERY |
| ISO-2-Code: | US |
| ISO-3-Code: | USA |
| Phonecode: | 1 |
Address Example
Example of standardized United States postal addresses.
Country Info
Full Country Name: United States of America
| Country Alpha-2 code | US |
|---|---|
| Country Alpha-3 code | USA |
| Numeric Code | 840 |
Timezone
The United States spans six primary time zones. Daylight Savings Time is observed in most states, except Hawaii and most of Arizona.
| Time Zone | UTC | DST |
|---|---|---|
| Eastern (ET) | UTC-5 | |
| Central (CT) | UTC-6 | |
| Mountain (MT) | UTC-7 | |
| Pacific (PT) | UTC-8 | |
| Alaska (AKT) | UTC-9 | |
| Hawaii–Aleutian (HAST) | UTC-10 |
Official Language
English is the official language used by the federal government of the United States and is the standard language for postal addresses.
Fun Fact
- The U.S. is the third most populous country in the world. (CIA)
- The U.S. is 3rd largest country in area globally, just behind Russia and Canada. (CIA)
- It also has the largest GDP at purchasing power parity (PPP), ahead of all other countries. (CIA)
- The median age is about 39 years, which is young compared to many European countries. (CIA)
- It is one of the world’s most linguistically diverse countries: besides English, hundreds of languages are spoken due to immigration and indigenous populations. (CIA)
- Major rivers such as the Mississippi, Missouri, Colorado, and Rio Grande play huge roles in the country’s geography, commerce, and history. (CIA)
- The U.S. has a high level of urbanization; a large percentage of the population lives in urban areas. (CIA)
- The U.S. has a very diverse geography: from Arctic tundra in Alaska to tropical in Hawaii, deserts in the Southwest, major mountain ranges, large freshwater systems, etc. (CIA)
Postal Authority
United States Postal Service (USPS) is an independent agency of the U.S. federal government that provides mail and package delivery to over 160 million addresses nationwide. Established in 1775 with Benjamin Franklin as the first Postmaster General, USPS operates a network of more than 31,000 retail post offices and delivers over 128 billion pieces of mail annually. Its services include domestic and international mail, Priority Mail, First-Class Mail, ZIP+4 enhanced delivery, and PO Boxes.
Reference: https://about.usps.com/
Postal Data & Certification
The United States Postal Service offers CASS™ certification (Coding Accuracy Support System) to ensure the accuracy of the address validation vendors using their data. Vendors must pass certification test to ensure all the rules set for each CASS™ Cycle is properly followed. CASS cycles are periodic updates to the validation rules, the latest one being CASS™ Cycle O which took effect in August of 2023.
In order to be CASS™ Certified, vendors must use the following data files:
- DPV: Delivery Point data
- LACSLink: Data to convert rural style addresses to city style addresses
- SuiteLink: Data to append missing suites to business addresses
Additionally, a host of other data is available from the USPS for additional verification, such as:
- RDI for identifying business vs residential addresses
- NCOA for converting change of address records to their new address
Melissa, founded in 1985, started as a provider of address validation and presorting in the US. We have been a CASS™ certified provider from the very beginning and continue to be the most advanced provider of address and full contact provider for the United States.
Postal Code Format
Format:
- Standard 5-digit ZIP Code appears to the right of the city & state.
- Optional ZIP+4 adds a hyphen and four extra digits for precise delivery.
Examples:
- Lake Forest, CA 92630
- Lake Forest, CA 92630-1234
Structure:
- The first digit represents a group of states.
- The next two digits identify a regional processing center.
- The last two digits indicate a specific post office. ZIP+4 narrows delivery further.
Name Conventions
Population Names
In the United States, names are predominately English/Latin, in the western naming format. It is common to have honorific (Mr or Mrs) preceding the forename and professional degrees to follow the surname (MD, Ph.D,):
[opt: title/ honorific] [given name] [opt: middle given name(s)] [FAMILY NAME] [opt: suffix /post nominal]
Examples:
- Mr. John Smith Sr.
- Dr. William Smith PhD MBA
- Mr. and Mrs. John and Jane Smith
There are no national naming laws in the U.S., and states generally allow broad flexibility. However, names may be rejected if they include numerals, symbols, or obscenities. Patrilineal naming is traditional, but individuals are free to retain, hyphenate, or create new surnames after marriage.
Honorifics such as Mr., Mrs., Dr., and professional post-nominals like MD, PhD, Esq., or CPA are frequently used in both formal and informal contexts.
Organizational Names:
Business entities in the United States are required to include legal identifiers depending on their type and state laws. Common suffixes include:
- Inc. (Incorporated)
- Corp. (Corporation)
- Co. (Company)
- LLC (Limited Liability Company)
- Ltd. (Limited)
Naming rules vary slightly by state, but in general, the entity type must be clearly reflected in the business name and the name must be distinguishable from existing registered businesses.
