748 area code — Colorado geographic
Area code 748 is a geographic code serving Colorado in the Mountain time zone. It has been in service since July 7, 2025. The same territory is also served by its overlay code (748/970 complex). Keep in mind the code identifies where the number was registered; the person calling may be elsewhere.
The code was carved out of 970 (2025).
The current NANPA exhaust forecast for the 748/970 complex is 4Q 2088.
Local calls inside 748 are dialed 10D; 1+10 digit permissible at service provider discretion..
Practical takeaway: the 748 label narrows geography to Colorado, the prefix narrows it to a locality, and neither authenticates a caller. Verification means calling back through a number you found yourself.
FAQ
Why am I getting spam calls from 748 numbers?
Scammers spoof real area codes so calls look legitimate. A displayed 748 number does not prove the call originated there — see our guide to spotting spoofed calls.
Where is a 748 number from?
748 is assigned to Colorado in the Mountain time zone. The three digits after the area code (the prefix) narrow it down to a rate center.
Is 748 a toll-free number?
No. 748 is a geographic code; calls are billed like any other domestic call. Toll-free codes are 800, 833, 844, 855, 866, 877 and 888.