Telecom Intelligence

Carrier lookup API

Telebase returns the carrier serving any phone number, along with the country, number type (mobile, landline or VoIP) and active status, in a single per-query API call. Send the number in E.164 format and receive a JSON response in real time. Pricing is $0.03 per query with no contract and no minimum spend.

Why carrier data is useful for fraud and KYC

A phone number's carrier tells you more than which network it is on. Carrier data surfaces anomalies that are hard to spot otherwise: a number registered to a foreign MVNO on an account claiming a local address, a sudden cluster of signups from the same wholesale carrier, or a consumer number routed through a VoIP provider. None of these alone is proof of fraud, but each one sharpens a risk decision at near-zero cost per query.

Carrier lookup is also useful for operational decisions: routing OTPs via the right channel, verifying that a number matches the country on a KYC form, and confirming a number is active before placing an outbound call.

What Telebase returns

• carrier: the network operator currently serving the number
• country: the country where the number is registered
• numberType: mobile, landline, fixedVoip, nonFixedVoip, tollFree, or voicemail
• active: whether the number is currently reachable on the carrier network
• simSwap: recent SIM swap signal, launching: returns UNKNOWN today while carrier registration is in progress

Example call

GET https://telebase.fatcatremote.com/api/lookup?phone=%2B447700900000
Authorization: Bearer tb_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxx

{
  "phoneNumber": "+447700900000",
  "active": true,
  "carrier": "EE",
  "country": "GB",
  "numberType": "mobile",
  "simSwap": "UNKNOWN",  // launching, not yet available
  "simSwapAt": null
}

simSwap returns UNKNOWN while the SIM swap feed is being registered with carriers. When live, it will return SWAPPED, NO_SWAP, or UNKNOWN.

Coverage

Carrier, country, number type and active status are live across GB, NL, DE and FR. Numbers must be passed in E.164 format, for example +447700900000 for a UK number or +31612345678 for a Dutch number. The leading + must be URL-encoded as %2B in the query string.