State ZIP Codes

Every US state has its own unique set of ZIP codes, ranging from Delaware's compact ~58 ZIP codes to Texas's sprawling ~1,935. Browsing ZIP codes by state is the natural starting point for territory planning, compliance mapping, campaign targeting, and geographic data analysis. Our State ZIP Codes tool gives you a complete, filterable directory of every active ZIP code in any state, organized with city names, county assignments, and population data.

Why ZIP Codes by State Matters

State-level ZIP code data is the foundation for an enormous range of operational tasks. Insurance companies must file products by state and ensure their rating territories (defined by ZIP code) cover every ZIP in each licensed state. Retailers designing delivery zones or store coverage maps need to know which ZIP codes belong to which state to apply state-specific rules. Marketing teams targeting by state must use the correct ZIP list to avoid over-reaching into neighboring states.

Compliance teams in financial services, healthcare, and legal industries maintain state-specific blacklists and whitelists — records that must not be contacted in certain states based on regulatory restrictions. These compliance rules are often implemented as ZIP code filters: block all records whose ZIP code belongs to a restricted state.

How ZIP Code Prefixes Map to States

The first three digits of a ZIP code identify a Sectional Center Facility (SCF), which generally aligns with state or regional mail processing hubs. This creates predictable ZIP prefix ranges for each state. California ZIP codes range from 900xx to 961xx. Texas spans 750xx to 799xx. New York spans 100xx to 149xx. Understanding these ranges helps analysts do quick sanity checks on ZIP code data: a ZIP starting with 9 that is classified as a Northeast state is almost certainly a data error.

Complete State ZIP Code Directories

A complete state ZIP code list is useful for: building a state-filtered mailing list; setting up geographic targeting in ad platforms; validating that a list vendor's ZIP code file doesn't contain out-of-state ZIPs in error; configuring shipping rate tables by state; and designing state-specific analytics dashboards.

Our tool returns for each ZIP in the state: the 5-digit ZIP code, the USPS preferred city name, the county, the timezone, population estimate, and ZIP code type. This comprehensive data enables immediate use in any downstream application without additional lookups.

State ZIP Code Population and Demographics

Combining state ZIP codes with Census ACS demographic data enables state-level market analysis at ZIP code granularity. Sum the population across all ZIPs in a state to get state total population. Calculate the median income across all ZIPs in a state to benchmark regional affluence. Identify the highest-population ZIPs in a state for market prioritization. Segment ZIPs by income bracket for tiered marketing strategies.

Texas: The State With the Most ZIP Codes

Texas leads all states with approximately 1,935 active ZIP codes — a reflection of its combination of large geographic area (268,596 square miles, the largest contiguous US state) and large population (~30 million, second largest by population). Texas spans multiple area code regions, three primary climate zones, five major metropolitan areas (Dallas-Fort Worth, Houston, San Antonio, Austin, El Paso), and covers everything from ultra-dense urban ZIP codes in downtown Dallas and Houston to vast rural ZIP codes in the Trans-Pecos region where a single ZIP may cover more territory than some northeastern states.

Delaware: The State With the Fewest ZIP Codes

Delaware, the smallest state by geographic area (1,982 square miles) and with ~1 million residents, has approximately 58 active ZIP codes — the fewest of any state. Most Delaware ZIP codes serve the three counties of New Castle, Kent, and Sussex, with the densest ZIP concentration around Wilmington in the north. Delaware ZIP codes begin with 197–199, a prefix range that is immediately recognizable in address data.

ZIP Code Lists for All 50 States Plus Territories

Beyond the 50 states and DC, US territories have their own ZIP code ranges. Puerto Rico uses 006xx–009xx. US Virgin Islands use 008xx (overlapping with New England, differentiated by the island-specific middle digits). Guam uses 969xx. American Samoa uses 96799. Northern Mariana Islands use 969xx. Military APO/FPO codes use various ranges. Our tool supports all of these for complete US address coverage.