Guides to US addresses and ZIP codes, page 22

Practical guides on address formats, ZIP codes, area codes and test data, plus reference pages for every state and major city.

Address basics
How to Write a Nebraska Address (With Examples)
Learn the correct Nebraska address format with real NE examples, apartment and PO Box formats and common mistakes to avoid.
City guides
Ogden, UT ZIP Codes, Area Codes and Address Format
Ogden, Utah ZIP codes, area codes, county and time zone, plus sample addresses and formatting tips for Ogden mail.
City guides
Los Angeles, CA ZIP Codes, Area Codes and Address Format
Los Angeles, California ZIP codes, area codes, county and time zone, plus sample addresses and formatting tips for Los Angeles mail.
City guides
Austin, TX ZIP Codes, Area Codes and Address Format
Austin, Texas ZIP codes, area codes, county and time zone, plus sample addresses and formatting tips for Austin mail.
City guides
Oakland, CA ZIP Codes, Area Codes and Address Format
Oakland, California ZIP codes, area codes, county and time zone, plus sample addresses and formatting tips for Oakland mail.
City guides
Camp H M Smith, HI ZIP Codes, Area Codes and Address Format
Camp H M Smith, Hawaii ZIP codes, area codes, county and time zone, plus sample addresses and formatting tips for Camp H M Smith mail.
Testing and development
Address Normalization and Duplicate Detection
How to normalize US addresses before saving them, so duplicates are easy to find and data stays clean for shipping and reporting.
Address basics
How to Format Apartment, Suite and Unit Numbers
Where apartment, suite, floor and unit numbers go in a US address, which abbreviations to use and how to handle long lines.
Address basics
How to Address Mail to the United States from Another Country
Formatting tips for sending letters and packages to US addresses from abroad, including the country line and ZIP code placement.
ZIP codes
What Is ZIP+4 and When Should You Use It?
ZIP+4 adds four digits to a five-digit ZIP code to pinpoint a delivery segment. Learn what the extra digits mean and when they help.
Phone numbers
US Area Codes and Phone Number Format Explained
How US phone numbers are structured, what area codes are, and why 555-0100 to 555-0199 numbers are safe for testing and fiction.
Address basics
How a US Mailing Address Is Structured, Line by Line
Learn the parts of a standard US mailing address: recipient, street line, secondary unit, city, state and ZIP code, with correct USPS order.
Responsible use
Why a Generated Address Should Never Be Used for Real Transactions
Generated addresses are for testing and learning. Here is why using one to sign up, order or verify identity can cause problems.
Address basics
Rural Route and Highway Contract Addresses
What rural route (RR) and highway contract (HC) addresses are, how to format them and why many have been converted to street addresses.
Address basics
PO Box vs Street Address: Key Differences
Compare PO Boxes and street addresses: how they are formatted, which carriers deliver to them and when businesses should accept each.
Testing and development
Using Generated Addresses for Software Testing: A Practical Guide
How QA teams and developers use realistic generated US addresses to test forms, databases, shipping logic and tax rules without real customer data.
ZIP codes
How ZIP Codes Are Assigned: The First Three Digits Explained
The first digit of a ZIP code marks a group of states, and the first three mark a sectional center facility. Here is how the system works.
Address basics
How to Write an Address on an Envelope
Where to place the delivery address, return address and stamp on a US envelope, with spacing tips that help automated sorting.
Address basics
USPS Street Suffix and Unit Abbreviations You Should Know
A practical reference for the USPS standard abbreviations for street suffixes like AVE and BLVD and unit designators like APT, STE and FL.
Address basics
US State Abbreviations: Complete List of Two-Letter Codes
The full list of USPS two-letter abbreviations for all 50 states and the District of Columbia, plus territory and military codes.
Testing and development
Address Form Validation Rules for Web Developers
Practical validation rules for US address forms: required fields, ZIP code patterns, state lists, length limits and friendly error messages.
Testing and development
Why QA Teams Should Avoid Real Customer Data in Testing
Using production customer data in test environments creates privacy and security risks. Here is why generated test data is the safer choice.
Testing and development
Generating Bulk Test Addresses as CSV and JSON
How to create and use bulk US test addresses in CSV and JSON formats for database seeding, imports and automated tests.
Geography
Counties, Cities and ZIP Codes: How US Geography Fits Together
Understand how counties, cities, places and ZIP codes relate in the United States, and why they often do not line up neatly.