Phone number prefix lookup
Paste phone numbers and see what the area code and prefix actually tell you about each line: where it was assigned, and whether it is toll-free, premium-rate, a service code or a Caribbean +1 number. Runs in your browser; nothing is uploaded.
10-digit numbers without + are read as US/Canada (+1).
Why the prefix can't tell mobile from landline
Every US and Canadian number is an area code, a three-digit prefix and a four-digit line number. Carriers receive numbers in blocks by area code and prefix, so a prefix once hinted at whether a number was a cell phone or a home line.
Number portability ended that. People keep their number when they switch from a landline to a mobile plan, or from a mobile carrier to a VoIP app, so the same prefix can hold all three line types. A list sorted by prefix will put landlines in your texting campaign and cell phones in your landline bucket.
What to do with the results
Pull the flagged rows first. Toll-free and premium numbers are almost never the person you want, and Caribbean +1 codes are international calls. The geographic numbers that remain still need a live check to sort mobile, landline and VoIP, and to find the ones that are disconnected.
Upload a CSV. Get back every number marked valid or dead, mobile, landline, VoIP or toll-free, with carrier.
Start 7-day free trial →Check one number free with the carrier lookup or landline checker. Flag toll-free numbers in bulk with the toll-free number checker, look up non-US numbers with the country code lookup, or read about VoIP number detection.
Questions
Can you tell if a number is a cell phone from its prefix?
Not reliably. Phone prefixes were once handed out in blocks to either wireless or wireline carriers, but since number portability a person can move a cell number to a landline or VoIP provider, or the other way around, and keep the same digits. The prefix shows who the block was assigned to, not what the line is today.
What can the prefix tell you, then?
The area code tells you the region a geographic number was assigned to, and flags special codes: toll-free (800, 833, 844, 855, 866, 877, 888), premium-rate 900 numbers, non-geographic service codes, and Caribbean countries that dial with +1 but bill as international calls.
What is the difference between an area code, a prefix and a line number?
In a US or Canadian number like (415) 555-2671, 415 is the area code (NPA), 555 is the prefix or exchange (NXX), and 2671 is the line number. The area code and prefix together identify the block of numbers a carrier was originally assigned.
Is my list uploaded anywhere?
No. The numbers are read in your browser. Nothing is sent to TrueSearch or anyone else, and nothing is stored after you close the page.
How do I find the real line type of every number?
Run a live carrier lookup. TrueSearch for Business checks each number in a CSV and returns valid or dead, mobile, landline, VoIP or toll-free, and the current carrier. You can try one number free with the carrier lookup.
This guide is general information, not legal advice. TrueSearch for Business checks validity, line type and carrier from licensed telecom data. It does not check the National Do Not Call Registry, state DNC lists or the FCC Reassigned Numbers Database. Not a consumer reporting agency; not for FCRA purposes.