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

Colorado (CO) operates within the 5-digit ZIP prefix range 800xx–816xx. Mail routed to state capital Denver and key regional centers such as Denver, Colorado Springs, Aurora adheres to these official USPS boundaries.

Which telephone area codes are valid for Colorado?

Colorado is served by 5 active North American Numbering Plan (NANPA) area codes: 303, 719, 720, 970, 983. Synthetic telephone numbers for Colorado use those area codes with a 555 exchange, which is reserved for fictitious use.

How many counties are in Colorado?

Colorado is divided into 64 counties, including major administrative regions such as Denver, El Paso, Arapahoe, Jefferson. Generated street addresses use those names.

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

High-altitude mountain community P.O. Box mandates (such as Aspen, Vail, Breckenridge) where USPS does not provide residential carrier delivery due to terrain and winter accessibility. Denver's strict alphanumeric named-street alphabetic grid (e.g., Albion, Bellaire, Clermont) running orthogonal to numbered avenues. All addresses generated on this platform format secondary unit designators (Apt, Ste, Fl) and street suffixes according to USPS CASS standards.

Are the Colorado addresses generated on this page real places?

No. All street numbers, recipient names, and telephone numbers generated for Colorado are entirely synthetic and randomized for software testing, database seed scripts, and form validation. They use Colorado ZIP codes from public USPS data and real city names, but they do not correspond to real individuals or private residences.

Random Colorado Address Generator

These addresses are randomly generated for software testing. They are not real people’s details: the street number, unit and recipient name are invented, and no record is checked for deliverability.

Randomly generated Colorado mailing addresses for software testing, form validation and staging data. Each record pairs a real Colorado city with a ZIP prefix that serves it and the county that city sits in, then adds a street number, a secondary unit designator and a recipient name that are invented.

Official Colorado Postal & Geographic Reference Specifications

Geographic & Postal Parameter	Official State Specification	Standardization Reference
Postal State Abbreviation	CO	USPS Publication 28 & ISO 3166-2:US
5-Digit ZIP Prefix Range	800xx–816xx	USPS prefix-to-state assignment
Administrative Jurisdictions	64 Total Counties	US Census Bureau regional boundaries
Active Area Codes (NANPA)	`303, 719, 720, 970, 983` (5 total)	North American Numbering Plan Administrator
State Capital	Denver	US Census Bureau
Primary Time Zone	Mountain Time (America/Denver, UTC-7 / UTC-6 DST)	IANA time zone database

Colorado Postal Geography & Key Cities

ZIP codes and Sectional Center Facilities are derived from public USPS ZIP code data, area codes from the North American Numbering Plan, and county names from US Census Bureau records. Street numbers and recipient names are synthetic, and nothing is checked against an address-verification service.

Cities the generator draws from:

Denver
Colorado Springs
Aurora
Fort Collins
Boulder
Lakewood

Key Counties & Administrative Jurisdictions

County boundaries determine local sales tax jurisdictions in Colorado:

Denver County
El Paso County
Arapahoe County
Jefferson County
Boulder County

Colorado Area Codes (CO)

Generated phone numbers use the area codes listed in the reference table above, paired with a 555 exchange so no number can reach a real line. Generate Colorado phone numbers.

Postal Delivery Standards & Format Nuances in Colorado

High-altitude mountain community P.O. Box mandates (such as Aspen, Vail, Breckenridge) where USPS does not provide residential carrier delivery due to terrain and winter accessibility.
Denver's strict alphanumeric named-street alphabetic grid (e.g., Albion, Bellaire, Clermont) running orthogonal to numbered avenues.

Colorado Address Examples in USPS Publication 28 Format

Residential Delivery Point:
100 Main St, Apt 4B Denver, CO 80202-1204

Commercial / Multi-Unit Delivery Point:
Colorado Logistics & Software Corp 500 Enterprise Way, Suite 300 Colorado Springs, CO 80903-4810

Frequently Asked Questions about Colorado Addresses

What ZIP codes does Colorado use for mail and package delivery?: Colorado (CO) operates within the 5-digit ZIP prefix range 800xx–816xx. Mail routed to state capital Denver and key regional centers such as Denver, Colorado Springs, Aurora adheres to these official USPS boundaries.
Which telephone area codes are valid for Colorado?: Colorado is served by 5 active North American Numbering Plan (NANPA) area codes: 303, 719, 720, 970, 983. Synthetic telephone numbers for Colorado use those area codes with a 555 exchange, which is reserved for fictitious use.
How many counties are in Colorado?: Colorado is divided into 64 counties, including major administrative regions such as Denver, El Paso, Arapahoe, Jefferson. Generated street addresses use those names.
What postal formatting conventions and addressing quirks are unique to Colorado?: High-altitude mountain community P.O. Box mandates (such as Aspen, Vail, Breckenridge) where USPS does not provide residential carrier delivery due to terrain and winter accessibility. Denver's strict alphanumeric named-street alphabetic grid (e.g., Albion, Bellaire, Clermont) running orthogonal to numbered avenues. All addresses generated on this platform format secondary unit designators (Apt, Ste, Fl) and street suffixes according to USPS CASS standards.
Are the Colorado addresses generated on this page real places?: No. All street numbers, recipient names, and telephone numbers generated for Colorado are entirely synthetic and randomized for software testing, database seed scripts, and form validation. They use Colorado ZIP codes from public USPS data and real city names, but they do not correspond to real individuals or private residences.

Nearby & Bordering States

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

Colorado ZIP Prefixes

The first three digits of a ZIP code place an address within Colorado. These are the prefixes assigned to the state:

800xx, 802xx, 803xx, 805xx, 809xx, 816xx

Which processing facility sorts a given prefix is set by the current USPS labeling list L005 and changes as processing is consolidated, so it is not reproduced here. Look up a ZIP prefix to see its state and generate ZIP codes inside it.