Concepts
What Is Phone Number Intelligence?
Phone number intelligence is the set of real-time signals a carrier-level lookup returns about a phone number: which carrier issued it, what type of number it is, whether it is currently active on the network, and whether its SIM has been recently swapped. These signals tell a fraud, compliance or KYC team things about a phone number that format validation and OTP verification cannot: whether the number is disposable, whether it matches the expected carrier and country, and whether it has been compromised.
The four core signals
Different providers use different names. The underlying signals are the same. Here is what each one is, what it tells you, and when it matters.
The mobile network operator or service provider that currently serves the number. A UK mobile number served by a legitimate carrier like EE, Three or Vodafone is lower risk than one served by a wholesale VoIP reseller. Carrier data also reveals porting: if a number was originally issued by one operator but now sits on another, the number has been ported, which may or may not be significant depending on context.
Whether the number is mobile, landline, fixed VoIP, non-fixed VoIP, toll-free or voicemail. This is the single most useful signal for onboarding fraud. Non-fixed VoIP numbers are cheap, disposable and disproportionately used for multi-accounting, promotional abuse and synthetic identity applications. Screening them at sign-up catches the cheapest and most common fraud vector.
Whether the number is currently reachable on the carrier network. A number that is disconnected, deactivated or unreachable is unlikely to belong to a real customer. The strength of this signal depends on the source: a network-level line-status check (HLR or SS7) is definitive; a format-validity check is weaker. Good providers surface the source so your risk engine can weight accordingly.
Whether the SIM card associated with the number has been recently changed. A recent SIM swap is the most common precursor to account takeover via OTP interception. The attacker ports or swaps the victim's number to a SIM they control, then intercepts the one-time passcode. SIM swap detection flags this before you send the OTP.
Phone intelligence vs phone verification vs phone validation
These three terms get used interchangeably. They are different things that answer different questions.
| Term | What it does | What it tells you |
|---|---|---|
| Phone validation | Checks format, length and country code against numbering plan rules | Whether the number could exist. Does not contact the carrier network. |
| Phone verification (OTP) | Sends a one-time passcode via SMS or voice and waits for the user to enter it | Whether the user currently possesses the device. Does not tell you what kind of number it is or who the carrier is. |
| Phone intelligence (carrier lookup) | Queries carrier records in real time and returns structured data about the number | Which carrier, what number type, whether active, whether the SIM was swapped. Does not require the user to do anything. |
Most fraud and KYC stacks need all three. Validation catches typos. Verification proves possession. Intelligence catches the cases the other two miss: a correctly formatted, successfully verified number that happens to be a disposable VoIP line, or a real mobile number whose SIM was swapped yesterday.
The difference between SIM swap detection, line type lookup and identity match
This is a common comparison question, and the answer is that they are three separate signals that catch different threat types. They are not interchangeable, and choosing between them depends on what you are trying to prevent.
Returns whether a number is mobile, landline, VoIP or another type. Use it at onboarding to screen out disposable and virtual numbers. It catches multi-accounting, promotional abuse and synthetic identity fraud. Available today from Telebase as the numberType field.
Returns whether the SIM card behind the number was recently changed. Use it before sending an OTP or authorising a high-value transaction. It catches account takeover where the attacker has taken control of the victim's number. Available on Telebase as the simSwap field.
Compares identity attributes (name, address, date of birth) against carrier-held subscriber records. Use it for know-your-customer checks where you need to confirm the person behind the number. This is a different category of API, typically offered through CAMARA Open Gateway or direct carrier integrations, and is not currently part of the Telebase product. See What is CAMARA Open Gateway? for more on this route.
In practice, a robust onboarding flow uses line type at sign-up, SIM swap before any OTP-gated action, and identity match only where regulatory requirements demand subscriber-level verification. They layer, they do not replace each other.
How Telebase returns these signals
A single GET request returns carrier, country, number type, active status and SIM swap status in one JSON response. There is no dashboard, no batch upload and no seat licence.
{
"phoneNumber": "+4915112345678",
"active": true,
"carrier": "Telekom Deutschland",
"country": "DE",
"numberType": "mobile",
"simSwap": true, // SIM was swapped in the last 48 hours
"simSwapAt": "2026-09-19T14:32:00Z",
"_meta": { "activeSource": "LINE_STATUS" }
}
This response shows a number whose SIM was recently swapped. A risk engine receiving this would block or step up verification before sending an OTP. See the field reference for the full response shape.
Where phone intelligence fits in a fraud or KYC stack
Phone intelligence sits between format validation (which you already do) and phone verification (OTP, which you probably already do too). It adds a passive, real-time check that requires no action from the customer and returns structured data your risk engine can consume directly.
Common integration points:
- Pre-OTP at onboarding: screen out VoIP and inactive numbers before spending money sending an SMS. See line type detection at onboarding.
- Ongoing transaction monitoring: check SIM swap status before authorising a high-value payment, crypto withdrawal or password reset. See SIM swap check before high-value transactions.
- Risk scoring: combine carrier, number type and active status into a composite risk score alongside your other signals. See building a risk score from telecom signals.
- Agent-based decisioning: feed the JSON response directly into an AI agent or automated workflow. See phone intelligence tools for AI agents.