Area code 303 — Denver, Colorado
- Area code
- 303
- Location
- Denver, Colorado
- Local time
- Mountain Time
Area code 303 covers Denver and surrounding communities in Colorado.
Updated 28 July 2026
Where is area code 303?
Area code 303 is in Denver, Colorado, covering Denver and surrounding communities in Colorado. All 303 numbers are on Mountain Time.
Cities
Denver
Is area code 303 a scam?
No. Area code 303 is a legitimate area code serving Denver since 1947. Scammers spoof caller ID to display 303 numbers, which is why complaints exist against a code that is itself genuine.
Neighbour spoofing is the reason a local-looking number is not a guarantee. A caller anywhere in the world can display a 303 number, and the number they display may belong to a real business in Denver that has nothing to do with the call.
- Area code 303 had 1,059 different numbers reported for spam calls in the 30 days to 28 July 2026.
- Area code 303 ranks 17th of 331 US geographic area codes by spam complaint volume.
- Of the 1,118 complaints about area code 303 in the 30 days to 28 July 2026, 59% were reported as a recorded message or robocall.
- The most reported subject on area code 303 is medical & prescriptions, appearing in 15% of its complaints in the 30 days to 28 July 2026.
Most reported numbers · last 30 days
| Number | Reports | Last reported |
|---|---|---|
| (303) 535-2362 | 7 | 1 day ago |
| (303) 535-2363 | 6 | 4 days ago |
| (303) 209-2049 | 4 | 15 days ago |
| (303) 343-2224 | 4 | 11 days ago |
| (303) 535-2371 | 4 | 7 days ago |
A number listed here may itself be a spoofing victim rather than the caller. These are unverified consumer reports.
Source: FTC Do Not Call Reported Calls Data, unverified consumer reports, retrieved 28 July 2026. Request a correction.
What these calls were about
Each figure is that subject’s share of every 303 complaint in the 30 days to 28 July 2026, as categorised by the consumer who reported it.
Medical & prescriptions
15% of reported 303 calls · 170 complaints
Calls pretending to be government, businesses, or family and friends
7% of reported 303 calls · 78 complaints
Home improvement & cleaning
6% of reported 303 calls · 63 complaints
Warranties & protection plans
3% of reported 303 calls · 33 complaints
Reducing your debt (credit cards, mortgage, student loans)
2% of reported 303 calls · 27 complaints
Businesses can prevent their own numbers from being mistaken for calls like these.
Calls from your 303 number not landing?
Why am I getting text messages from area code 303?
Texts from 303 numbers follow the same pattern as calls — mostly local businesses and services. Treat any text asking for payment or credentials as suspect regardless of the code.
The common patterns are a wrong-number opener that turns into conversation, an unsolicited job offer, and a crypto or investment tip. Do not reply, do not follow the link, and forward the message to 7726 (SPAM) to report it to your carrier.
Area codes that overlay 303
Area code 303 shares its geographic footprint with 2 other codes: 720, 983. Overlays are laid over an existing area rather than splitting it, so all local calls require the full ten-digit number.
Who works in the Denver area?
Area code 303 is one of the originals, in service since 1947, and it covers Denver, Colorado and its inner metro. The economy it serves is large and white-collar. The Denver metro produced $311.9 billion in GDP in 2023, and the city hosts the headquarters of eight Fortune 500 firms. Per Data USA (2024), the biggest industries employing Denver residents are professional, scientific, and technical services (about 68,000 workers), health care and social assistance (about 56,500), and educational services (about 36,400). The best-paid sectors tell the rest of the story: corporate management and oil and gas extraction top the wage table, a legacy of Denver's role as the finance and energy hub of the Rocky Mountain West.
Who lives in the 303 region
Denver is a city of transplants and professionals. The 2024 population was 718,877 with a median age of 35.3 and a median household income of $94,718 (Data USA). Management is the single most common occupation among residents. About 28% of the city is Hispanic, and Spanish is the most widely spoken language after English, with Colorado's foreign-born population led by people born in Mexico. Vietnamese and Amharic communities are present but far smaller. The median property value of $616,000 (2024) reflects a decade of in-migration that has made talent plentiful and housing expensive.
What a 303 number signals to a caller
A 303 number carries weight locally. Because the code predates the 720 and 983 overlays by half a century, callers describe 303 as the "old Denver" prefix, the one long-established firms tend to hold. All three codes cover the same ground and ten-digit dialing is universal. Business is conducted on Mountain Time, which matters for out-of-region callers: Denver's workday starts two hours after New York's, and a 9 a.m. Eastern call lands at 7 a.m. here. Meetings are generally informal in dress and punctual in practice.
Questions
Where is area code 303?
Area code 303 serves Denver and surrounding communities in Colorado. It is in the Mountain Time zone.
What state is area code 303 in?
Area code 303 is in Colorado. It is not in Akron — those are area code 330.
Is area code 303 toll free?
No. Area code 303 is a geographic area code serving Denver, Colorado. The toll-free codes are 800, 833, 844, 855, 866, 877, 888, and a call to a 303 number is charged at your normal rate.
Why am I getting calls from 303?
Calls displaying a 303 number come from businesses and individuals in the Denver area, and from anywhere at all when caller ID is spoofed to look local. 1,059 303 numbers were reported to the FTC in the 30 days to 28 July 2026.
How do I block calls from area code 303?
Both iOS and Android can silence calls from unknown numbers, and every major US carrier offers free call-blocking. Blocking the whole of area code 303 is rarely worth it, because spoofed numbers change constantly and you would lose legitimate calls from Denver.