How to Find ZIP Codes by State

In the United States, ZIP codes are organized by state and delivery area, so one of the easiest ways to locate them is to start with the state. Whether you need a single ZIP code for mailing or a full list for research or business, several reliable tools let you browse or search ZIP codes by state in just a few clicks. zippingus

Using the USPS ZIP Code Lookup

The U.S. Postal Service (USPS) provides a free online ZIP Code Lookup that lets you find ZIP codes by state, city, or address. On the USPS site you can: tools.usps

• Choose the “Find by City and State” option, then pick a state from the dropdown and a city to see all ZIP codes used there. tools.usps
• Use the ZIP+4 lookup to get more precise codes for specific addresses within a state. smarty

Because USPS is the official source, this method is ideal for shipping, forms, and any situation where accuracy matters. tools.usps

State‑based ZIP code directories and maps

Several websites let you explore ZIP codes by state through interactive maps or tables. Common features include: unitedstateszipcodes

• A state list or dropdown where you select a state, then see all ZIP codes and cities within that state. codigo-postal
• ZIP code maps that show boundaries and corresponding ZIP codes for each area. geoapify

These tools are useful if you want to compare ZIP codes across a whole state, study regional coverage, or pick a ZIP based on location instead of a street name. zippingus

Downloadable ZIP code lists by state

For businesses, developers, or analysts, several sites offer CSV or database downloads of all U.S. ZIP codes, grouped by state and city. Typical features include: simplemaps

• Free or paid ZIP‑code databases with fields for ZIP, city, state, latitude/longitude, and demographics. simplemaps
• Filters that let you extract all ZIP codes for a single state (for example, “all ZIP codes in Texas”). postalpro.usps

These files are helpful for bulk geocoding, mailing‑list validation, or building ZIP‑based filters in your own applications. smarty

Quick manual method: State‑range references

The IRS and other government sources publish ZIP‑code range tables by state, which show the approximate leading digits used in each state (for example, “800nn–816nn” for Colorado). These tables are not meant for precise mailing but can help you: irs

• Check whether a ZIP code falls within the expected range for a given state. irs
• Spot possible errors when you see a ZIP code that clearly does not match the state’s pattern. irs

Example workflow to find a ZIP by state

1. Identify the state where your address is located (for example, “NC – North Carolina”). tools.usps
2. Visit the USPS ZIP Code Lookup or a ZIP‑code directory and choose “Find by City and State.” unitedstateszipcodes
3. Select the state, then type the city; the page will list all ZIP codes used in that city‑state pair. tools.usps

This approach works the same way for small towns and large cities, and ensures you choose the correct ZIP for your mailing address. smarty

References

• U.S. Postal Service, “ZIP Code™ Lookup” and related tools (USPS and PostalPro) for official ZIP‑code assignments by state, city, and address. postalpro.usps
• Third‑party ZIP‑code lookup and mapping sites such as UnitedStatesZipCodes.org and ZippingUS, which provide searchable ZIP lists and maps organized by state. codigo-postal
• ZIP‑code database and download services (for example, Geoapify and SimpleMaps) that offer statewide ZIP tables in CSV or SQL format. geoapify
• IRS publication on Standard Postal Service State Abbreviations and ZIP Code ranges, which shows approximate ZIP patterns by state. irs