Phone Intelligence

Validate user phone numbers and prevent fake numbers, voips, and fraud.

The Verisoul Phone Intelligence API provides phone number intelligence, specifically focusing on number validity and type. This guide will walk you through how to use the API, integrate it into your systems, and understand the information returned by the API.


Verisoul's Phone Intelligence works globally.

How to Use the API

The API endpoint for phone intelligence requests receives a phone number and outputs intelligence about that phone number. Including details about it's validity, type, country, and carrier.


Visit the API Reference to learn how to integrate Phone Intelligence API

Use Phone Intelligence to prevent fake signups and fraud

Understanding the type of phone number can help in preventing fake signups, duplicate sign-ups, and fraud. Real, mobile phone numbers are generally expensive, and it's uncommon for users to have multiple of them. However, some users try to create multiple accounts with temporary phone numbers, VoIP numbers (like Google Voice, Twilio, etc.).

To prevent fake signups, we recommend ensuring sign-ups are:

  1. Unique numbers: ensure phone numbers are only used to sign up for 1 active account at a time
  2. Valid numbers: ensure phone numbers are legitimate
  3. Mobile numbers: we strongly recommend ensuring that users sign up with mobile phone numbers. We recommend blocking or requiring additional verification or scrutiny for other line types


See our line type risk levels and recommendations below

Response Fields and Meanings

phone_numberCleaned and normalized phone number
validWhether the phone number exists
calling_country_codeInternational dialing prefix of the phone number (e.g., +1)
country_codeTwo-letter country code of the phone number (e.g., US)
carrier_nameName of the phone carrier
line_typeType of phone number (see below for full list and explanation)

Line Types and associated risk levels

Line TypeDescription and AnalysisRisk LevelCommon?Recommendation
mobileCapable of receiving SMS messages - often used for legitimate accounts, and often unique to each personlowcommonallow
landlineNot capable of receiving SMS messages; less commonly used for account sign-upsmediummoderateblock
fixedVoIPVirtual phone number tied to a physical device and a physical address. Often used by businesses and residential customers that need traceable phone servicemediummoderateadditional verification or monitor account
nonFixedVoIPVirtual phone number that is not tied to a device or address - like Google VoIP, Twilio, etc. Commonly used to create temporary phone numbers used for fraudhighcommonblock
tollFreeA toll-free number often associated with a business; very uncommonly used for sign-upsmediumuncommonadditional verification or monitor account
premiumA premium number with higher chargeshighuncommonblock
personalA phone number designated for personal usemediumuncommonadditional verification or monitor account
sharedCostA phone number with charges partially paid by the calling partyhighuncommonblock
uanA universal access number routing to different destinationshighuncommonblock
voicemailA phone number associated with a voicemail servicehighuncommonblock
pagerA phone number associated with a pager devicehighuncommonblock
unknownA valid phone number but the line type could not be determinedmediumuncommonadditional verification or monitor account


Only mobile, landline, fixedVoIP, and nonFixedVoIP will return carrier data

Carrier data is not available for phone number types: personal, tollFree, premium, sharedCost, uan, voicemail, pager, or unknown. In these cases country_code, and carrier_name values will be null.