The Phone Codes You Dial in Colorado
Local calls take all 10 digits everywhere in the state. That single rule covers the Denver overlay region, the 719 south, and the 970 west alike. Toll calls may need a 1 in front, and operator-assisted calls may use a 0, depending on the provider. NANPA's planning documents for Colorado spell out those three patterns exactly.
| Call Type | Phone Code Format | Example |
|---|---|---|
| Local, anywhere in Colorado | 10 digits, area code plus number | NPA-NXX-XXXX |
| Long distance / toll | 1 + 10 digits | 1-NPA-NXX-XXXX |
| Operator-assisted | 0 + 10 digits | 0-NPA-NXX-XXXX |
| Toll-free | 1 + toll-free code + 7 digits | 1-800-NXX-XXXX |
| International | 011 + country code + number | 011, then the destination digits |
| Service shortcuts | 3-digit N11 code | 988 |
The statewide part is newer than it looks. Southern and western Colorado dialed 7 digits locally until late 2021, so older signs and letterheads there may still show short numbers that no longer connect as printed.
N11 Phone Codes Across Colorado
Nine three-digit codes route straight to services, and most of them land somewhere specific in Colorado. Two of them handle life and safety, and those two never change, no matter which area code serves your town.
| N11 Phone Code | What It Reaches in Colorado |
|---|---|
| 211 | 211 Colorado community services, also 866-760-6489 or text a ZIP to 898-211 |
| 311 | City services only where a local government runs it; Denver is the main example |
| 411 | Carrier directory assistance, which may carry a fee or be unavailable |
| 511 | CDOT's voice-activated traffic line, or 1-800-288-1047 from outside the state |
| 611 | Your own phone carrier's repair and customer service |
| 711 | Relay Colorado, the telecommunications relay service |
| 811 | Colorado 811 utility locates, required by law at least three business days before digging |
| 911 | Emergency police, fire, and medical, unaffected by any overlay |
| 988 | The 988 Colorado Mental Health Line by call or text, at all hours |
Important: 911 and 988 always work as three digits in Colorado. Every other shortcut depends on your carrier or your city, so test before you rely on one.
Star Phone Codes on Colorado Lines
Star codes, formally vertical service codes, flip features on and off for a single line. NANPA assigns them nationally, but support varies by carrier, so a code that works on a Denver landline may do nothing on a mountain wireless plan. Colorado adds one of its own: dialing *277 reports aggressive driving to the State Patrol in real time.
| Star Phone Code | Action |
|---|---|
| *57 | Trace the last threatening or harassing call for law enforcement follow-up |
| *60 | Block selected callers where the carrier supports it |
| *66 | Redial automatically when a busy line frees up |
| *67 | Hide your caller ID for the next call |
| *69 | Return the last incoming call |
| *70 | Turn off call waiting for the current call |
| *72 / *73 | Start and stop call forwarding |
| *77 | Reject calls from callers who block their ID |
| *82 | Unblock your caller ID for one call on a blocked line |
The full national assignment list lives on the NANPA vertical service codes page.
NANPA itself cautions that an assignment does not guarantee a code works without conflict everywhere, so confirm a star phone code with your own carrier before an important use like a call trace.
Area Phone Codes in the Colorado Mix
The area code is just the first phone code in every number, and Colorado carries six of them in three regional groups. Reading the group tells you roughly where a number was issued.
- 303, 720, 983 - Denver, Boulder, and north-central Colorado, layered since 1998
- 719 - Colorado Springs, Pueblo, and the south, on its own since 1988
- 970, 748 - northern and western Colorado, with 748 added in 2025
Geography, history, and per-code coverage get their full treatment on the Colorado phone area codes page.
Toll-Free Codes Dialed from Colorado
Seven prefixes mark a call as toll-free today: 800, 888, 877, 866, 855, 844, and 833. Each new one opened as the older pools filled. The FCC stresses that they are not interchangeable, so 1-800 and 1-888 versions of the same seven digits reach two different subscribers. A few more ranges sit reserved for future toll-free use, which is why unfamiliar 8XX prefixes deserve a quick check before you trust them.
Toll-free numbers bill the called party, which is why agencies and hotlines lean on them. Colorado examples run through this whole site, from the state's 800-922-1987 dig line to DORA's 1-800-886-7675 consumer line.
Country Code +1 and Dialing Abroad
Colorado sits inside the North American Numbering Plan, the +1 country code region that covers the US, Canada, and more than twenty other territories. Nobody dials +1 for a call across town, but the code matters at the borders of the system.
- Calling abroad from a Colorado landline: dial 011, then the country code, then the number.
- Calling abroad from a mobile: long-press 0 for the plus sign, then dial the country code and number.
- Receiving a call from overseas: the caller dials their exit code, then 1, then your 10-digit Colorado number.
Carrier behavior with the plus-sign format varies, so international travelers should confirm dialing details with their own provider before leaving.
Colorado Exchange Phone Codes
The middle three digits, the NXX, form the exchange phone code. Each one belongs to a rate center, a billing and routing unit that often outruns city limits. NANPA's Colorado files show 303-202 held by Qwest in Denver, 720-383 held by Verizon Wireless, and 719-200 held by T-Mobile in Colorado Springs, with hundreds more across centers from Alamosa to Telluride. An area code offers 792 assignable prefixes, which is exactly the resource that overlays protect.
One caution keeps repeating in the source data. Number portability lets a customer keep a number while switching carriers, so an exchange code proves original assignment, not the current provider. Treat prefix lookups as history, and use a live carrier tool for the present.
Note: Full routing-grade exchange data sits in the licensed LERG guide, so free public files will always trail the carriers' own records slightly.
How 988 Reshaped Colorado Dialing
The newest three-digit phone code rewrote the state's local dialing. When the FCC created 988 for the Suicide and Crisis Lifeline, the digits 988 already existed as an ordinary exchange prefix inside 719 and 970. A 7-digit local call starting with 988 would have collided with the new shortcut. Colorado's fix was permissive 10-digit dialing from April 24, 2021, then mandatory 10-digit dialing on October 24, 2021.
The code has kept evolving since. Federal georouting rules now aim wireless 988 calls at a crisis center near the caller rather than one matched to the number's area code, a meaningful change in a state where many residents carry numbers from somewhere else.
Spam Labels and the Likely Spam Code
The words on your screen during an incoming call are a phone code of a different kind. STIR/SHAKEN, the FCC's caller-ID authentication framework, makes carriers digitally sign calls as they pass between networks. Signed calls can show as verified, while analytics engines add labels like Likely Spam. Authentication proves the number was not forged in transit, not that the caller is honest, and a legitimate Colorado number can occasionally get mislabeled.
Label problems and robocall complaints both route to the FCC Consumer Complaint Center, which also handles spoofing of your own number.
The FCC answers 1-888-225-5322 by phone. Its 2025 enforcement removed more than 1,200 non-compliant voice providers from the Robocall Mitigation Database, which cut off network access for the worst traffic sources.
No Call Lists for Colorado Phones
Colorado keeps its own no-call program alongside the federal one, and the state advises registering on both. Colorado No Call takes registrations and complaints online or by its automated line at 303-776-2678 or 800-309-7041. Its complaint form screens each report, since political, survey-only, and debt-collection calls follow different rules.
Have the caller's number, the date and time, and the message content ready before filing. The federal side runs through the FTC's unwanted call reporting page or 1-888-382-1222.
The FTC form asks whether the call was prerecorded and what was being sold, details that decide whether a telemarketer broke the registry rules.
Phone Code Definitions
Six terms cover nearly all the numbering jargon a Colorado caller will meet.
- NPA
- Numbering Plan Area, the 3-digit area code that starts every North American number.
- NXX
- The exchange or central office code, the 3 digits after the area code.
- N11
- The 3-digit service shortcuts: 211, 311, 411, 511, 611, 711, 811, and 911, joined by 988.
- Vertical Service Code
- A star followed by two digits that switches a calling feature on or off.
- Toll-Free Prefix
- A code such as 800 or 833 that bills the call to the party receiving it.
- NANP
- The North American Numbering Plan, the +1 region that includes Colorado.
How to Check a Colorado Phone Code
Verification takes minutes. NANPA's public reports confirm whether an area code or exchange assignment is real and which rate center holds it. The FCC's consumer guides explain what each N11 shortcut does and how the toll-free system works. Between the two, any phone code that shows up on a Colorado caller ID can be checked against the official record.
Note: A real phone code does not vouch for a caller, because spoofing copies legitimate codes easily; verify the person through a published directory number.