- Location
- Denver, Colorado
- Service began
- 1947
- The time zone
- Mountain time
- Calls within the area
- 10-digit dialing
- Rate centre list
- 13
- Exhaust projection
- 2069
- Code for the country
- +1 (United States)
The source is NANPA public reports, including the area code report and rate-centre report, with a file dated 11/01/2026. The projected exhaust year comes from NANPA projections 2026-1 (April 2026). This site is not an official NANPA site.
Get your 303 number
There are two routes to a 303 number. With its plan, a provider hands out a new number, chosen at sign-up from the pool it holds in this code. Numbers already in a seller’s inventory are listed at a one-time price and often have a pattern. You then transfer your chosen number to a provider.
Providers ranked by first-year cost
| Provider | Cheapest plan | First year | Link |
|---|---|---|---|
 Free app | Basic (Just for me), free | $0 | Open Google Voice |
 Free app | Free plan, free | $0 | Open TextNow |
 Developer API | Pay-as-you-go local number, $1.15 a month | $13.80 | Open Twilio |
 Second-number app | Standard, $3.99 a month billed yearly | $47.99 | Open Burner |
 Toll-free specialist | Solo, $6.99 a month billed yearly | $84 | Open UniTel Voice |
 Second-number app | Deluxe (local number), $6.99 a month billed yearly | $102.88 | Open GoDaddy Conversations (formerly Smartline) |
Sellers listing local numbers
| Seller | What it sells | Listed price | Monthly fee | Link |
|---|---|---|---|---|
 Marketplace | Local numbers | From $9 one-time | None stated | Search at Exclusive Digits |
 Marketplace | Local and toll-free | From $9.95 one-time | $2.99 a month | Search at NumberBarn |
 Number broker | Local and toll-free | From $99 one-time | None stated | Search at RingBoost |
 Number broker | Local and toll-free | From $100 one-time | None stated | Search at PhoneNumberExpert |
| 212areacode.comNumber broker | Local numbers | From $150 one-time | None stated | Search at 212areacode.com |
Some sellers and providers may pay us a referral fee. The order stays based on first-year cost and never changes. How we earn
Places in the 303 area code
For 303, NANPA lists 13 rate centres. Each one is a local calling area where numbers get assigned:
Strasburg, Roggen, Longmont, Keenesburg, Hudson, Georgetown, Fort Lupton, Denver, Deer Trail, Deckers, Byers, Bennett and Allenspark-lyons.
Other related area codes
Codes 720 and 983 serve the same area and share one pool of numbers. Any of these codes can supply a new number in this area, so ask for the one you want.
Colorado also uses the area codes 719, 970 and 748.
The city guides cover Denver area codes.
303 area code questions
What area does 303 serve?
Denver, Colorado, and the area around Denver-Aurora-Centennial, CO, are served by area code 303.
What country code does a 303 number use?
+1. Because 303 belongs to the North American Numbering Plan, from abroad you dial +1 303 and then the 7-digit number.
What time is it in the 303 area code?
Area code 303 uses Mountain time.
Who places calls from a 303 number?
This code covers homes, mobiles and local businesses. It also covers callers who fake a local number. What a 303 number shows on your screen is where that number was assigned, not the caller’s identity.