How to find out where a phone number is from
Read the number's structure
A US number has three parts: area code (NPA), prefix (NXX) and line number — 212-555-0100 breaks into area code 212, prefix 555, line 0100. The area code narrows the number to a region; the prefix pins it to a rate center, the billing locality where the number block was issued.
Look up the area code
Enter the three-digit code in the search on our home page or browse the area code index. The code page shows the state, major cities, time zone and whether the code shares territory with overlays. Toll-free codes (800, 833, 844, 855, 866, 877, 888) have no geography at all.
Check the prefix
For a six-digit lookup (e.g. 646-212), the prefix table of the area code lists the rate center and the carrier that holds the block, from NANPA's public central-office code records. That is the finest location granularity that exists in public numbering data — street addresses or names are not part of it.
Know the limits
Number portability lets people keep numbers when they move or switch carriers, and VoIP services hand out numbers from any rate center. Caller ID spoofing can fake the display entirely. So a number's origin is a fact about the number, not proof of the caller's current location.
Sources
FAQ
Can I find out who owns a number?
Not from numbering data. Public NANPA records identify carriers and localities, never individuals. Services claiming to name a number's owner rely on scraped or purchased personal data — treat them with caution.
Why does a mobile number show the wrong city?
The number keeps the rate center where it was first issued. If the owner moved or ported the number, the geography is historical.