Prefix 303-834 — Longmont, CO

NANPA CO code assignment, current as of July 28, 2026.

The 303-834 prefix belongs to area code 303 and is anchored to the Longmont rate center (CO). In NANP terms, the prefix — or NXX — determines the rate center a number is billed against.

For routing purposes it sits in LATA 656. Numbers here keep Mountain time.

NANPA's central-office code records list CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CO (OCN 6567) as the code holder, assigned September 27, 2006. Because 303-834 participates in thousands-block pooling, individual 1,000-number blocks may belong to other carriers than the code holder.

Caller ID showing 303-834 is not proof the call came from Longmont: 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

FAQ

Where is 303-834 located?

The prefix is assigned to the Longmont rate center in CO, area code 303.

Which company owns 303-834 numbers?

CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CO 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 303-834 safe to answer?

The prefix itself says nothing about the caller. Legitimate Longmont businesses and spoofed robocalls can both display it. Never share personal data with an unverified inbound caller.