What is the 303 area code?

The 303 area code is Denver's original area code, assigned in 1947 as one of the original North American Numbering Plan area codes. It originally covered the entire state of Colorado. Today it covers Denver and its immediate surrounding communities, including Lakewood, Aurora, Englewood, Littleton, and Golden. It's culturally synonymous with Denver identity.

What is the 720 area code?

The 720 area code was added in 1998 as an overlay for the 303 area code. As Denver's population grew and phone numbers were exhausted, 720 was introduced to add more number availability. 720 numbers are assigned to the same geographic area as 303 — the Denver metro area. New numbers issued since 1998 often have 720 prefixes.

What is the difference between 303 and 720?

Geographically, there is no difference — both cover the same metro Denver area. The distinction is temporal: 303 numbers are older (pre-1998) and carry a cultural cachet as 'original Denver.' 720 numbers are newer. Many Denverites with a 303 number hold onto it as a point of local pride. New residents or businesses typically receive 720 numbers.

Are there other Denver area codes?

Yes — 983 was added as another Denver metro overlay code. Outside the immediate Denver metro, Colorado uses 719 (southern Colorado, Colorado Springs) and 970 (northern and western Colorado, including Fort Collins, Boulder, and the Western Slope).

Why is 303 important to Denver culture?

303 has become an identity marker for Denver natives and long-time residents. Being a '303 native' signals that you were here before the city's recent population explosion. Phrases like 'born and raised 303' are common. Businesses use '303' in their names as a signal of Denver authenticity. And one local event platform — 303Happenings — literally has 303 in its name.

Is Boulder also a 303 area code?

No — Boulder and the surrounding area primarily uses 720 and 303 for numbers assigned before the separation, but the Boulder-Fort Collins corridor is increasingly 970. Boulder is technically within the 303/720 overlay zone due to its proximity to Denver.

303Happenings

Denver, CO

Denver Area Codes: 303 vs 720

303 is more than just a phone number — it's a Denver identity. Here's the story behind Colorado's most iconic area code, and what the difference between 303 and 720 actually means.

1947

303 introduced

1998

720 added

Same

Geographic area

303

1947

Status: Original Denver area code
Coverage: Denver metro (original)
Cultural vibe: Old-school Denver, local pride

720

1998

Status: Overlay code
Coverage: Denver metro (same area)
Cultural vibe: Newcomer signal (not an insult)

All Colorado Area Codes

Area Code	Region	Notable Cities	Introduced
303	Denver Metro	Denver, Lakewood, Aurora, Englewood	1947
720	Denver Metro overlay	Same as 303 area	1998
983	Denver Metro overlay	Same as 303/720 area	2021
719	Southern Colorado	Colorado Springs, Pueblo, Trinidad	1995
970	Northern & Western CO	Fort Collins, Boulder, Vail, Aspen	1995

Why 303 Is a Denver Identity

In a city that has grown explosively — nearly doubling in population since 2000 — "303" has become shorthand for Denver authenticity. A 303 area code signals that you were here before the condos, the influx, and the transplants. It's a small but meaningful badge of local credibility.

You'll see 303 in business names, T-shirts, tattoos, and license plate frames. The number appears in rap lyrics, sports chants, and neighborhood pride posts. When someone says "I'm a 303 native," they mean something specific about their relationship to the city.

And yes — we're one of them. 303Happenings is named for the area code because Denver is our city, and this is where we're rooted.

Denver Area Codes: Frequently Asked Questions

Denver Area Codes: 303 vs 720 Explained | 303Happenings | 303Happenings