Prefix 303-476 — Denver, CO
The 303-476 prefix belongs to area code 303 and is anchored to the Denver rate center (CO). In NANP terms, the prefix — or NXX — determines the rate center a number is billed against.
Denver is part of the Denver-Aurora-Centennial, CO Metropolitan Statistical Area. For routing purposes it sits in LATA 656. Numbers here keep Mountain time.
NANPA's central-office code records list MCIMETRO ACCESS TRANSMISSION SERVICES LLC (OCN 7229) as the code holder. Because 303-476 participates in thousands-block pooling, individual 1,000-number blocks may belong to other carriers than the code holder.
Caller ID showing 303-476 is not proof the call came from Denver: spoofing and porting both detach numbers from their origin. To verify a caller, hang up and dial the organization's published number, and report suspicious calls to the FTC.
Neighboring prefixes
| Prefix | Rate center | Code holder |
|---|---|---|
| 303-473 | Denver | QWEST CORPORATION |
| 303-474 | Denver | TELEPORT COMMUNICATIONS AMERICA, LLC - CO |
| 303-475 | Denver | NEW CINGULAR WIRELESS PCS, LLC |
| 303-477 | Denver | QWEST CORPORATION |
| 303-478 | Denver | NEW CINGULAR WIRELESS PCS, LLC |
| 303-479 | Denver | TELEPORT COMMUNICATIONS AMERICA, LLC - CO |
FAQ
Where is 303-476 located?
The prefix is assigned to the Denver rate center in CO, area code 303. It is part of the Denver-Aurora-Centennial, CO Metropolitan Statistical Area.
Which company owns 303-476 numbers?
MCIMETRO ACCESS TRANSMISSION SERVICES LLC holds the code, but the prefix is pooled — individual thousands-blocks can be assigned to other carriers, and numbers may be ported to any provider.
Is a call from 303-476 safe to answer?
The prefix itself says nothing about the caller. Legitimate Denver businesses and spoofed robocalls can both display it. Never share personal data with an unverified inbound caller.