748 Area Code — Colorado
Area code 748 serves Colorado in the Mountain time zone, in service since 2025. Consumers have filed 23 unwanted-call complaints against 15 different 748 numbers. Look up the exact number that called you below.
Reported 748 numbers
No single 748 number has enough complaints yet for a full report page, so none are listed. Look up the exact number that called you: the lookup works on every US number, whether or not it has complaint history.
Is it getting worse?
FCC complaints about 748 numbers peaked in 2020 (8); the FTC's daily Do Not Call data has carried most of the volume since mid-2026.
FCC complaints per year
Years shown as '15 to '26; the current year is partial.
Carriers operating in 748
NANPA has assigned 8 748 prefixes (NPA-NXX central-office codes) across 8 rate centers: 0% to wireless carriers, 100% to landline and VoIP operators; 100% are pooled blocks shared by several carriers. 8 prefixes were assigned in the last 12 months (newest 2026-10-19). The carrier holding a prefix is who the number was issued through. It says nothing about who is calling, since caller ID is routinely spoofed.
| Carrier | Type | Prefixes | Rate centers | Newest assignment |
|---|---|---|---|---|
| Onvoy (Sinch) | Competitive / VoIP (CLEC) | 5(63%) | 5 | 2026-10-19 |
| Wide Voice, LLC | Competitive / VoIP (CLEC) | 3(38%) | 3 | 2026-10-19 |
Largest rate centers (exchanges) by prefixes: Durango (1), Eagle (1), Estes Park (1), Fraser (1), Gilcrest (1), Greeley (1), Ignacio (1), Mead (1). Source: NANPA Central Office Code Utilized Assignments (public, refreshed weekly).
What to do about calls from 748 numbers
Before you call back
Report it in Colorado
- Unwanted sales calls and robocalls: donotcall.gov (FTC). Scams and fraud: ReportFraud.ftc.gov.
- Spoofing, texts and call-blocking problems: FCC consumer complaints.
- State complaints: Colorado Attorney General.
- Colorado is one of the states that maintains its own Do Not Call registry alongside the federal National Do Not Call Registry, so telemarketers calling Colorado numbers are expected to check both lists. Registering on the federal list at donotcall.gov is free and never expires; the state list is administered separately and may have its own registration process and renewal period.
Your FTC and FCC reports are published (without your name or number) in the datasets this page is built from. How to report unwanted calls.
Area code 748: questions answered from the data
Where is area code 748?
Area code 748 serves Colorado. It has been in service since July 7, 2025.
What time zone is area code 748 in?
Area code 748 is in the Mountain time zone (UTC−7, or UTC−6 during daylight saving time). The current local time is shown at the top of this page.
How do I report a 748 scam call in Colorado?
Report unwanted sales calls and robocalls to the FTC at donotcall.gov, and scams to ReportFraud.ftc.gov. The FCC takes complaints at consumercomplaints.fcc.gov. In Colorado, the Colorado Attorney General also handles consumer complaints about scam calls. Reports feed the public data this page is built from.
Overlay and nearby area codes
Sources: FTC Do Not Call complaints (unverified consumer reports), published every weekday and available here from Jul 24; FCC Consumer Complaint Data, public record, imported nightly; NANPA numbering records. A number appearing here means consumers reported calls that displayed it. Caller ID can be spoofed.