What ZIP codes does Wyoming use for mail and package delivery?

Wyoming (WY) operates within the 5-digit ZIP prefix range 820xx–831xx, covering numeric postal codes from 82001 – 83128. Mail routed to state capital Cheyenne and key regional centers such as Cheyenne, Casper, Laramie adheres to these official USPS boundaries.

Which telephone area codes are valid for Wyoming?

Wyoming is served by a single statewide area code: 307. Because Wyoming operates under a single numbering plan area (NPA), every valid Wyoming phone number begins with 307 — there are no regional sub-assignments to account for in test data. Synthetic telephone numbers generated for Wyoming strictly use area code 307 with verified local exchanges to match authentic state dial plans.

How many counties are in Wyoming?

Wyoming is divided into 23 counties, including major administrative regions such as Laramie, Natrona, Campbell, Sweetwater. Generated street addresses reflect these authentic jurisdictional subdivisions and their corresponding postal distribution points.

What postal formatting conventions and addressing quirks are unique to Wyoming?

Single statewide 307 area code spanning over 97,000 square miles with the lowest total population in the United States across 23 counties. Remote high-plains ranch star routes and Yellowstone / Grand Teton national park postal stations. All addresses generated on this platform format secondary unit designators (Apt, Ste, Fl) and street suffixes according to USPS CASS standards.

Are the Wyoming addresses generated on this page real places?

No. All street numbers, recipient names, and telephone numbers generated for Wyoming are entirely synthetic and randomized for software testing, database seed scripts, and form validation. While they use authentic Wyoming ZIP codes (820xx–831xx), real city names (Cheyenne, Casper), and verified area codes (307), they do not correspond to real individuals or private residences.

Random Wyoming Address Generator

Wyoming ZIP codes span the 820xx–831xx range (82001 – 83128) across 23 counties with 1 active telephone area code (307).

Generate a realistic, USPS Publication 28-compliant random Wyoming address with authentic postal routing, real ZIP codes, and local area codes. Featuring verified ZIP prefix coverage across 820xx–831xx, realistic street grids from Cheyenne and Casper, official area codes (307), and accurate county assignments. Engineered specifically for QA automation, form validation, and software testing.

Official Wyoming Postal & Geographic Reference Specifications

Geographic & Postal Parameter	Official State Specification	Standardization Reference
Postal State Abbreviation	WY	USPS Publication 28 & ISO 3166-2:US
5-Digit ZIP Prefix Range	820xx–831xx	USPS Sectional Center Facilities (SCFs)
5-Digit ZIP Numeric Span	`82001 – 83128`	Lowest to highest active postal delivery codes
Administrative Jurisdictions	23 Total Counties	US Census Bureau regional boundaries
Active Area Codes (NANPA)	`307` (1 total)	North American Numbering Plan Administrator
Capital & Distribution Centers	Cheyenne (Capital), Cheyenne, Casper, Laramie	Primary municipal carrier distribution hubs
Primary Time Zone	Mountain Time (America/Denver, UTC-7 / UTC-6 DST)	Regional postal dispatch & timestamp alignment
Authoritative Validation Source	Wyoming Public Service Commission & NANPA	Official state regulatory authority

Wyoming Postal Geography & Key Cities

State Capital: Cheyenne | Postal Code: WY | Total Counties: 23 Counties | ZIP Prefix Range: 820xx–831xx

Verified Data Authority: Wyoming Public Service Commission & NANPA

Major municipal distribution centers:

Cheyenne
Casper
Laramie
Gillette
Rock Springs

Key Counties & Administrative Jurisdictions

County boundaries dictate local sales tax jurisdictions and carrier route groupings across Wyoming:

Laramie County
Natrona County
Campbell County
Sweetwater County

Real Wyoming Area Codes (WY)

1 active numbering plan area (NPA) serving 23 jurisdictions across Wyoming.

Active North American Numbering Plan area codes: 307

Postal Delivery Standards & Format Nuances in Wyoming

Single statewide 307 area code spanning over 97,000 square miles with the lowest total population in the United States across 23 counties.
Remote high-plains ranch star routes and Yellowstone / Grand Teton national park postal stations.

Standard USPS Publication 28 Test Examples for Wyoming

Residential Delivery Point:
100 Main St, Apt 4B Cheyenne, WY 82001-1204

Commercial / Multi-Unit Delivery Point:
Wyoming Logistics & Software Corp 500 Enterprise Way, Suite 300 Casper, WY 82601-4810

Frequently Asked Questions about Wyoming Addresses

What ZIP codes does Wyoming use for mail and package delivery?: Wyoming (WY) operates within the 5-digit ZIP prefix range 820xx–831xx, covering numeric postal codes from 82001 – 83128. Mail routed to state capital Cheyenne and key regional centers such as Cheyenne, Casper, Laramie adheres to these official USPS boundaries.
Which telephone area codes are valid for Wyoming?: Wyoming is served by a single statewide area code: 307. Because Wyoming operates under a single numbering plan area (NPA), every valid Wyoming phone number begins with 307 — there are no regional sub-assignments to account for in test data. Synthetic telephone numbers generated for Wyoming strictly use area code 307 with verified local exchanges to match authentic state dial plans.
How many counties are in Wyoming?: Wyoming is divided into 23 counties, including major administrative regions such as Laramie, Natrona, Campbell, Sweetwater. Generated street addresses reflect these authentic jurisdictional subdivisions and their corresponding postal distribution points.
What postal formatting conventions and addressing quirks are unique to Wyoming?: Single statewide 307 area code spanning over 97,000 square miles with the lowest total population in the United States across 23 counties. Remote high-plains ranch star routes and Yellowstone / Grand Teton national park postal stations. All addresses generated on this platform format secondary unit designators (Apt, Ste, Fl) and street suffixes according to USPS CASS standards.
Are the Wyoming addresses generated on this page real places?: No. All street numbers, recipient names, and telephone numbers generated for Wyoming are entirely synthetic and randomized for software testing, database seed scripts, and form validation. While they use authentic Wyoming ZIP codes (820xx–831xx), real city names (Cheyenne, Casper), and verified area codes (307), they do not correspond to real individuals or private residences.

Nearby & Bordering States

Explore test address generators for states sharing a geographic border with WY:

Wyoming ZIP Prefixes and Sectional Center Facilities

Mail addressed to Wyoming is sorted through the processing facilities below before local delivery. The first three digits of a ZIP code identify which one, so the prefix alone places an address within the state.

ZIP prefix	Sectional Center Facility	County
820xx	Cheyenne / Laramie	Laramie County
826xx	Casper	Natrona County
827xx	Gillette	Campbell County
828xx	Sheridan	Sheridan County
829xx	Rock Springs / Green River	Sweetwater County
830xx	Jackson / Teton	Teton County

These 6 prefixes cover the 820xx–831xx range. Look up any ZIP prefix to see its facility and generate valid ZIP codes inside it.