Free tool · No sign-up · US and international numbers
Type any phone number and find out whether it is a VoIP line, a mobile or a landline, which carrier serves it today and where it was issued, including most app-based numbers such as Google Voice and TextNow. It is the same carrier check CallFlow runs on every inbound call before it reaches a customer's team.
Last reviewed 12 October 2026 by the CallFlow Engineering Team. How the check works and where the data comes from.
Example results
Three real lookups run with this tool on 12 October 2026, against the published numbers of the organisations named. Results can change when a number is ported.
Dialpad main line
(415) 469-1690
A business VoIP provider's own switchboard: VoIP line type, and the carrier field names the wholesale network behind it rather than the brand on the website.
White House comment line
(202) 456-1111
A traditional fixed line: landline class of service, a named incumbent carrier and the city the number was allocated to.
Apple Support
(800) 275-2273
Toll-free numbers are routed by the toll-free database rather than owned by one network, so the carrier field is empty by design and the location is the whole country.
What you get back
Three facts the phone network keeps about every assigned number — and, deliberately, nothing about the person using it.
Mobile, landline, VoIP, toll-free, premium-rate or pager — the class of service the number's current carrier has registered for it.
The network the number is served by today. If it has been ported, you see the new carrier, not the one that originally issued the number.
The country the number belongs to and, where the numbering plan carries it, the region or city the number was allocated to.
What it does not do: reverse lookups, owner names, addresses, or call history. This is a line-type and carrier check, not a people search.
Step by step
Four steps, about ten seconds. The same routine works for a cell-phone-or-landline check.
Type it as you would dial it at home, or in international format with a plus sign and the country code. For a number outside the United States, pick the country first or include the code.
The result says Mobile, Landline, VoIP or Toll-free. VoIP means the number is delivered over the internet by a VoIP provider instead of to a SIM card or a copper line.
The carrier of record is the network or VoIP provider serving the number today, and the location is where the number was allocated. A VoIP line type with a wholesale carrier name is the usual signature of an app-based number.
Plenty of legitimate businesses run on VoIP. For a suspicious caller, weigh the line type together with behaviour: very short calls, hang-ups on answer, repeat attempts and calls outside business hours.
None of these prove anything on their own, because a VoIP number looks exactly like any other number. Together they are a reasonable prompt to run the check above.
How the check works
A number's area code tells you where it was issued. The carrier database tells you what it is today.
Every phone number is assigned to a carrier, and every carrier registers what kind of service each block of its numbers carries. When numbers move between carriers, the number-portability database records the move. The lookup reads those records for the number you enter: the carrier currently serving it, the class of service that carrier has registered, and the country and region the number belongs to. For mobile numbers in most countries, the network itself confirms the current home carrier.
Area codes stopped being a reliable guide years ago. People keep their mobile number through moves and carrier changes, and VoIP providers issue numbers from every area code. Carrier-of-record data is the only check that reflects the number as it stands today, which is why call-screening systems, dialers and fraud teams rely on it rather than on prefix tables.
Side by side
A VoIP number is neither a cell phone nor a landline. This is how the three classes of service differ and how each one shows up in a lookup.
| Cell phone (mobile) | Landline | VoIP | |
|---|---|---|---|
| How the line is delivered | SIM card on a mobile network | Copper or fibre line to a fixed address | Internet connection to an app, softphone or IP desk phone |
| How it is obtained | Carrier contract or prepaid SIM, usually with identity checks | Service installed at a physical address | Online sign-up in minutes, often free or a few dollars a month |
| Tied to a place? | No, it travels with the person | Yes, a fixed service address | No, and the area code is chosen by the user |
| Receives text messages? | Yes | No | Depends on the provider |
| What the lookup shows | Mobile, with the mobile network | Landline, with the carrier | VoIP, with the provider or its wholesale carrier (some business lines are registered as Landline) |
| Share of unwanted calls | Low | Low | High: cheap to obtain in bulk and easy to discard |
Some lookup services split VoIP into fixed VoIP (a business phone system with a service address) and non-fixed VoIP (an app-based number with no fixed address). This tool reports the class of service the carrier registered; a business VoIP system registered as a landline shows as Landline with its internet-phone carrier.
Why VoIP matters
VoIP is not the problem. The economics of VoIP numbers are.
A VoIP number costs cents, is issued in seconds and can be dropped the moment it is flagged. That is exactly what a robocaller, a one-ring scam or a fraud ring wants from a phone number, and it is why a disproportionate share of unwanted calls to business lines arrive from VoIP ranges. A mobile number, by contrast, is tied to a SIM, a contract and usually an identity check.
For a business receiving calls, that makes the line type of the caller a useful first signal. It should never be the only one: plenty of legitimate companies run their phones on VoIP, including most call centres and many small businesses. The useful pattern is VoIP plus behaviour — short calls, hang-ups on answer, the same number hitting several of your lines, or bursts outside business hours.
That combination is what CallFlow's Spam Shield applies to every inbound call on a customer's numbers: the same carrier check you just ran, joined with per-caller rate limits, repeat-caller tracking and SIP response-code analysis, before the phone ever rings on an agent's desk.
Checking numbers one at a time is fine for a suspicious voicemail. For the numbers your business answers, CallFlow runs this check on every call and routes or blocks on the result.
Mobile or landline
Outbound teams check line type for a practical reason: the rules for calling and texting a mobile phone are stricter than for a landline. In the United States, for example, automated or pre-recorded calls and text messages to a mobile number generally require the recipient's prior express consent, and the consent standard is higher for marketing. Knowing which numbers in a list are mobile is the first step in keeping a campaign on the right side of those rules. Text messages, obviously, only reach mobiles at all.
Inbound teams care for a different reason. A mobile caller is reachable later by SMS, a landline caller is not, and a VoIP caller may not be reachable at all once the call ends. Capturing the line type alongside the call record lets a team pick the right follow-up channel without a second lookup.
This page is a technical tool, not legal advice. Consent and calling-time requirements differ by country and by state; check the rules that apply to your calls.
FAQ
Straight answers to the questions people type into search engines about VoIP numbers, line types and what a free lookup can and cannot tell you.
You cannot tell from the digits: a VoIP number has the same country code, area code and length as any other number. The reliable way is a carrier lookup, which returns the number's current carrier of record and the class of service registered for it. Enter the number above and the result says Mobile, Landline or VoIP, with the carrier and location. Without a tool the only hints are indirect: a blank or generic caller ID name, a number that cannot be reached after the call, or a caller whose number keeps changing.
Exactly like any other phone number. In the United States it is a normal 10-digit number with a geographic area code, and VoIP providers issue numbers from every area code as well as from the toll-free ranges. There is no VoIP prefix and no visual tell, which is why the only dependable check is the carrier record behind the number rather than its format.
Neither. VoIP is a third class of service: the number is routed over the internet to an app, a softphone or an IP desk phone instead of to a SIM card or a copper line. Lookup services report it as VoIP; some split it further into fixed VoIP, for business phone systems with a service address, and non-fixed VoIP, for app-based numbers with no fixed address. Carriers register some business VoIP lines as landlines, so a Landline result with an internet-phone carrier can still be a VoIP phone system in practice.
Usually, yes. App-based numbers such as Google Voice, TextNow or TextFree are registered as VoIP, and the carrier field shows the provider itself or the wholesale carrier that supplies the app with its numbers. Read the two together: a VoIP line type with a wholesale carrier name is the typical signature of an app number. A few app providers obtain numbers that are registered as mobile or landline, so there are exceptions.
Partly. A lookup like this one traces the number to its carrier or VoIP provider and to the area it was allocated to, which is what most people need to decide whether to answer or call back. It does not reveal the account holder. The provider does know who opened the account, and law enforcement or a court can obtain that through a subpoena or legal request to the provider; nobody else can. The location shown is where the number was issued, not where the phone is right now.
Run the number through the lookup and read the Carrier field. It is the carrier of record today, taken from carrier and number-portability data, so a number that has been ported shows its new carrier rather than the one that originally issued the block. For a number on a reseller, the result can show the host network the reseller rides on.
This one is free with no account and no card: 15 checks a day per visitor, each returning the line type, the carrier of record and the country. The limit exists because every check queries live carrier data that costs money. What free lookups of this kind do not include is the owner's name or address; that is a different product called a reverse lookup, and this page is not one.
Not from the number alone. VoIP providers do not publish directories, and a line-type lookup reports the provider, not the subscriber. If the number is harassing or defrauding you, report it to your carrier and, in the United States, to the FCC or FTC, or to the police; they can compel the provider to identify the account. If the number is calling your business line, a CallFlow account can block that caller, or every VoIP caller, automatically.
The lookup tells you whether the number is valid for its country and whether carrier records currently assign it to a carrier. A number with no record is usually in a range that has not been assigned to any carrier, or is not a real number. It cannot tell you whether a specific line in an assigned range has been disconnected, whether the handset is switched on, or whether a call will be answered.
Whether the number is a valid, assigned number, what kind of line it is (mobile, landline, VoIP, toll-free and so on), the carrier it is currently registered with, and the country or region the number belongs to. It does not tell you who owns the number.
Every number is assigned to a carrier, and carriers register what kind of service each block of numbers carries. The check looks the number up against those carrier and number-portability records, so a number that was ported from a landline carrier to a mobile one shows up as mobile under its current carrier.
Carrier-of-record data is accurate for the large majority of numbers, with known blind spots: numbers on resellers that ride another carrier's network may show the host carrier, a recent port can take a few days to appear, and some app-based numbers are registered as mobile or landline by the wholesale carrier that issued them.
Not by itself. Plenty of legitimate businesses run on VoIP. VoIP numbers are simply cheap to obtain in bulk and easy to discard, which is why robocallers and fraud rings favour them. Treat the line type as one signal, and look at behaviour as well, such as call volume, hang-ups and repeat attempts.
Yes. Pick the country from the selector, or type the number in international format with a plus and the country code and the selector is ignored. Mobile numbers in most countries return a line type and carrier; coverage for landlines varies by country.
No. This is a line-type and carrier check, not a reverse directory or a people search. It reports what the phone network knows about the number, not about the person using it.
The result of a check is kept for a while so that the same number does not have to be looked up again, and the request is counted against the daily allowance for your connection. Nothing about you is attached to the number, and the tool has no login.
About this tool
This page is built and maintained by the CallFlow Engineering Team at ALERTSIO LLC, the company behind the CallFlow call-routing platform. The same line-type check runs on every inbound call to our customers' numbers, where it feeds Spam Shield's VoIP-caller blocking, so the results on this page are the ones our own routing decisions depend on, not a separate demo dataset.
Each check queries live carrier-of-record and number-portability data for the exact number you enter and keeps the answer briefly so a repeated check does not cost a second query. There are no scraped directories, no user-submitted reports and no guesses from area-code tables. Where the data has known blind spots, resellers, very recent ports and some app-based numbers, the section above says so.
The copy on this page was last reviewed on 12 October 2026. If a result looks wrong for a number you know well, tell us; carrier records do carry errors and we would rather know.
What VoIP service is and how it differs from traditional phone service.
Why a number's original area-code assignment no longer tells you its carrier.
Why the number on your display can differ from the line that placed the call.
How area codes and number blocks are assigned to carriers in the US, Canada and the Caribbean.
Get a toll-free or local number, route calls to the right people, and let Spam Shield screen every caller before the phone rings.