303 Area Code

The 303 area code is part of the North American Numbering Plan (NANP) and serves the Denver metropolitan area and north-central Colorado, USA. Established in 1947 as one of the original area codes, 303 originally covered the entire state of Colorado but has since been split and overlaid due to population growth and increased demand for telephone numbers.

Understanding the 303 Area Code

The 303 area code covers Denver, Boulder, Lakewood, Arvada, Westminster, and surrounding cities and suburbs. It provides landline, mobile, and VoIP services. The overlay area code 720 is also used in the same geographic region, making 10-digit dialing mandatory for all local calls.

303 Area Code Map and Geographic Location

The 303 area code map encompasses north-central Colorado, primarily Denver and its metropolitan suburbs, extending into parts of Boulder and Jefferson counties. It includes urban, suburban, and select rural areas, serving as a key communications hub in the region.

All Major Cities and Regions in the 303 Area Code

Denver
Boulder
Lakewood
Arvada
Westminster
Aurora (partially)
Golden
Littleton
Longmont

Counties Covered by the 303 Area Code

Denver County
Boulder County
Jefferson County
Adams County (partial)
Arapahoe County (partial)

ZIP Codes within the 303 Telephone Zone (Examples)

80202 - Denver
80301 - Boulder
80226 - Lakewood
80003 - Arvada
80031 - Westminster
80222 - Aurora
80401 - Golden
80120 - Littleton
80501 - Longmont

Time Zone

The 303 area code is located in the Mountain Time Zone (MT), observing Mountain Standard Time (MST, UTC-7) in winter and Mountain Daylight Time (MDT, UTC-6) during daylight saving time.

Dialing, Phone & Service Details

Local dialing: 10-digit dialing is required due to overlay with area code 720.
Long-distance calls within the USA: Dial 1 + 303 + 7-digit number.
International calls: Dial your country�s exit code + 1 + 303 + 7-digit number.
Services: The 303 area code is used for landline phones, mobile devices, VoIP services, and business telecommunications.

Why the 303 Area Code Matters

The 303 area code is central to Colorado�s telecommunications network, serving the Denver metropolitan area, major educational institutions, businesses, and government offices. Many residents and organizations prefer 303 numbers for their association with the region�s identity and history.

What area code is 303? / Where's area code 303?

What area code is 303? � 303 is the telephone area code serving Denver, Boulder, Lakewood, Arvada, Westminster, and surrounding regions in Colorado, USA.

Where's area code 303? � It is located in north-central Colorado, primarily covering Denver and neighboring counties.

Frequently Asked Questions (FAQ) about 303 Area Code

What is the 303 area code?

303 serves the Denver metropolitan area and surrounding cities in north-central Colorado.

When was the 303 area code created?

It was established in 1947 as one of the original area codes in the United States.

Where is area code 303 located?

It is located in north-central Colorado, covering Denver and surrounding counties.

What time zone is 303 in?

The 303 area code follows Mountain Time (MST/MDT).

Which counties are included in 303?

Denver, Boulder, Jefferson, Adams (partial), and Arapahoe (partial).

Feature	Details
Area Code	303 (Overlay: 720)
Region Covered	Denver metropolitan area and north-central Colorado, USA
Established	1947 (original NANP code)
Time Zone	Mountain Time (MST/MDT)
Major Cities	Denver, Boulder, Lakewood, Arvada, Westminster
ZIP Range	80202-80501 (examples above)
Services	Landline, mobile, VoIP, business
Dialing	10-digit dialing; international format +1 303 NXX XXXX
Country	United States of America

Ares Code	Office / Place	Address
303 Area Code	University of Colorado Boulder	1669 Euclid Ave, Boulder, CO 80309
303 Area Code	University of Denver	2199 S University Blvd, Denver, CO 80208
303 Area Code	Metropolitan State University of Denver	890 Auraria Pkwy, Denver, CO 80204
303 Area Code	Community College of Denver	1111 W Colfax Ave, Denver, CO 80204
303 Area Code	Colorado Christian University	8787 W Alameda Ave, Lakewood, CO 80226
303 Area Code	Community College of Aurora	16000 E CentreTech Pkwy, Aurora, CO 80011
303 Area Code	Colorado School of Mines	1500 Illinois St, Golden, CO 80401
303 Area Code	Denver Health Medical Center	777 Bannock St, Denver, CO 80204
303 Area Code	UCHealth University of Colorado Hospital	12605 E 16th Ave, Aurora, CO 80045
303 Area Code	Rose Medical Center	4567 E 9th Ave, Denver, CO 80220
303 Area Code	St. Anthony Hospital	11600 W 2nd Pl, Lakewood, CO 80228
303 Area Code	Boulder Community Health	4747 Arapahoe Ave, Boulder, CO 80303
303 Area Code	SCL Health Lutheran Medical Center	8300 W 38th Ave, Wheat Ridge, CO 80033
303 Area Code	FirstBank	10403 W Colfax Ave, Lakewood, CO 80215
303 Area Code	Wells Fargo	1740 Broadway, Denver, CO 80274
303 Area Code	Chase Bank	1301 Canyon Blvd, Boulder, CO 80302
303 Area Code	KeyBank	13770 E Quincy Ave, Aurora, CO 80015
303 Area Code	Bank of the West	1801 Jackson St, Golden, CO 80401
303 Area Code	Colorado State Capitol	200 E Colfax Ave, Denver, CO 80203
303 Area Code	Denver City & County Building	1437 Bannock St, Denver, CO 80202
303 Area Code	Colorado Supreme Court	2 E 14th Ave, Denver, CO 80203
303 Area Code	Boulder County Courthouse	1777 6th St, Boulder, CO 80302
303 Area Code	Jefferson County Courthouse	100 Jefferson County Pkwy, Golden, CO 80419
303 Area Code	Denver Art Museum	100 W 14th Ave Pkwy, Denver, CO 80204
303 Area Code	Denver Museum of Nature & Science	2001 Colorado Blvd, Denver, CO 80205
303 Area Code	History Colorado Center	1200 Broadway, Denver, CO 80203
303 Area Code	Colorado Railroad Museum	17155 W 44th Ave, Golden, CO 80403
303 Area Code	Museum of Boulder	2205 Broadway, Boulder, CO 80302
303 Area Code	Molly Brown House Museum	1340 Pennsylvania St, Denver, CO 80203
303 Area Code	Denver Botanic Gardens	1007 York St, Denver, CO 80206
303 Area Code	Denver Zoo	2300 Steele St, Denver, CO 80205
303 Area Code	Red Rocks Amphitheatre	18300 W Alameda Pkwy, Morrison, CO 80465
303 Area Code	Pearl Street Mall	1942 Broadway, Boulder, CO 80302
303 Area Code	Lookout Mountain	987 Lookout Mountain Rd, Golden, CO 80401
303 Area Code	Bear Creek Lake Park	15600 W Morrison Rd, Lakewood, CO 80228
303 Area Code	Denver Public Library � Central	10 W 14th Ave Pkwy, Denver, CO 80204
303 Area Code	Aurora Public Library	14949 E Alameda Pkwy, Aurora, CO 80012
303 Area Code	Boulder Public Library � Main	1001 Arapahoe Ave, Boulder, CO 80302
303 Area Code	Jefferson County Public Library	10200 W 20th Ave, Lakewood, CO 80215
303 Area Code	Denver International Airport (DEN)	8500 Pe�a Blvd, Denver, CO 80249
303 Area Code	Union Station	1701 Wynkoop St, Denver, CO 80202
303 Area Code	RTD Aurora Metro Station	15023 E Centrepoint Dr, Aurora, CO 80012
303 Area Code	RTD Boulder Transit Center	1800 14th St, Boulder, CO 80302
303 Area Code	Empower Field at Mile High (Broncos)	1701 Bryant St, Denver, CO 80204
303 Area Code	Ball Arena (Nuggets/Avalanche)	1000 Chopper Cir, Denver, CO 80204
303 Area Code	Coors Field (Rockies)	2001 Blake St, Denver, CO 80205
303 Area Code	Folsom Field (CU Buffaloes)	2400 Colorado Ave, Boulder, CO 80302
303 Area Code	Dick�s Sporting Goods Park (Rapids)	6000 Victory Way, Commerce City, CO 80022

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