Phone Lookup API

Phone Lookup API for Identity & Risk Signals

Turn any phone number into a structured identity profile. ClearCheck Data returns carrier data, line type, risk score, linked email addresses, social profiles, and digital signals — all in one API call.

Carrier, line type, country, and active status
Risk score and spam / fraud indicators
Linked email addresses, social profiles, and messaging apps
Identity confidence score (0–10) and linked digital signals
PH
Phone Lookup
ClearCheck Data Engine
Completed
+1 (415) 555-2671
Carrier
Verizon Wireless
Verified
Line Type
Mobile · Active
Confirmed
Reputation Score
Safe · 0.12 / Low Risk
Clean
Social Profiles
4 accounts found
Enriched
Identity Score
7.4 / 10 · Strong
Matched
Signal confidence94/100

From a Phone Number to a Full Identity Signal Set

The Phone Lookup API accepts any E.164-formatted phone number and returns a normalized set of enrichment signals — carrier metadata, network type, activity indicators, risk scores, and linked identity data — in a single structured JSON response.

Carrier & Network Data

Identify the carrier, network type (mobile, landline, VoIP, prepaid), and home country for any phone number. Useful for routing decisions, fraud detection, and onboarding risk scoring.

Linked Email Discovery

Returns email addresses found to be associated with this phone number. Use them to cross-reference records or continue enrichment with the Email Lookup API.

Fraud Risk Signals

Receive a composite risk score and spam flag based on fraud pattern signals, abuse history, and network-level indicators. Use these signals to trigger additional review or auto-block high-risk numbers.

Linked Identity Signals

Discover which messaging platforms, social applications, or digital services are associated with this phone number — providing a richer picture of the identity behind the identifier.

Location Signals

Detect the registered country, region, and roaming status for the number. Flag numbers in high-risk regions or mismatched against user-submitted location data.

Confidence Score

Each lookup returns a score from 0 to 10. Higher means more consistent signals. Use it directly in your risk rules to approve, flag, or escalate accounts.

What You Send

A phone number in international format is all you need. Pass it with your API key and an optional reference ID.

Phone Number

International E.164 format — e.g. +14155552671. Covers US, EU, and global numbers.

API Key

Sent as a Bearer token in the Authorization header. Always kept server-side — never in browser code.

Lookup ID

A reference integer you assign. Returned as-is in the response so you can match results to your own records.

What You Get Back

Every completed lookup returns a structured JSON object. Here is what each field means and how to use it.

carrierThe mobile operator that owns this number — useful for routing decisions and detecting virtual operators.
line_typeMobile, landline, VoIP, or prepaid. VoIP and prepaid lines carry higher fraud risk by default.
countryWhere the number is registered. A mismatch with the user’s stated location is a red flag worth investigating.
risk_scoreA 0–1 number. Above 0.6 is worth a closer look. You define your own threshold in your rules engine.
spam_flagTrue if the number appears in known spam or abuse databases — treat this as a hard block signal.
linked_emailsEmail addresses associated with this number. Pass them to the Email Lookup API for deeper enrichment.
linked_profilesSocial network and public profile handles connected to this number, where detectable.
linked_appsMessaging platform registrations — e.g. WhatsApp, Telegram — associated with this number.
identity_score0–10 composite score. Score of 7+ means strong, consistent signals. Use it directly in your risk rules.

Submit, Receive, Poll, Parse

The phone lookup runs through an async enrichment pipeline. Submit your request, hold the job ID, and poll when ready. Your backend keeps processing without waiting.

1

Submit Phone Number

POST the phone number with your Bearer API key. The endpoint accepts E.164-formatted numbers globally.

2

Receive Job ID

The API responds immediately with a numeric job ID and status “progress”. No waiting required at this step.

3

Poll for Completion

Query the monitor endpoint using the job ID. When status changes to “completed”, the full signal set is ready.

4

Parse & Route

Receive normalized JSON. Route risk scores to your rules engine, store carrier data in your CRM, or trigger review workflows.

How to Make a Phone Lookup Call

Send one POST request with the phone number and your API key. Get a job ID back straight away — no waiting. Poll once to pick up the full result when ready.

The same endpoint handles all lookup types. Change lookup_type to switch between phone, email, name, or image enrichment — everything else stays the same.

Your API key stays on the server — never in the browser
Non-blocking — submit and move on, collect results when ready
Same JSON structure for every lookup type — easy to build once
Works with any phone number in E.164 format, anywhere in the world

Docs are currently on our existing portal and will move to the ClearCheck Data portal soon.

POST /api/developer/combined_phone JSON
// 1. Submit lookup
POST /api/developer/combined_phone
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
{
  "lookup_type": "phone",
  "value":       "+14155552671",
  "lookup_id":   42
}

// 2. Initial response
{
  "id":     8821043,
  "status": "progress"
}

// 3. Poll for result
GET /api/request-monitor/api-usage/8821043

// 4. Completed response
{
  "status": "completed",
  "data": {
    "carrier":    "Example Carrier",
    "line_type":  "mobile",
    "country":    "US",
    "active":     true,
    "risk_score": 0.12,
    "confidence": 0.94
  }
}

Who Uses Phone Lookup and Why

Phone enrichment signals support a wide range of business workflows — from account onboarding and fraud prevention to compliance screening and CRM data quality.

Fraud Prevention

Flag high-risk numbers at account registration or transaction time. Risk scores, spam flags, and VoIP/prepaid detection help intercept fake accounts before they cause damage.

KYC & Onboarding

Enrich submitted phone numbers during identity verification flows. Carrier data, line type, and active status supplement other identity signals for stronger onboarding decisions.

Risk Orchestration

Feed phone signals directly into your rules engine or risk scoring platform. Structured JSON integrates with any decision system without additional transformation.

E-commerce & Marketplaces

Verify buyer and seller contact data before transactions. Detect disposable numbers, prepaid burners, and VoIP lines commonly associated with chargeback fraud and account abuse.

OSINT & Investigations

Enrich phone numbers submitted during investigations. Carrier data, linked app signals, and geographic information help build a structured picture of the number’s owner.

Marketing & CRM Hygiene

Validate phone numbers in contact lists before outreach. Filter disconnected, inactive, or invalid numbers to improve deliverability, reduce waste, and keep CRM data clean.

Frequently Asked Questions

The Phone Lookup API accepts numbers in E.164 international format (e.g. +14155552671). This format includes the country code prefixed with a + sign. US numbers should be formatted as +1XXXXXXXXXX. The API supports phone numbers from all major countries and regions.
The API uses an async enrichment pipeline. After submitting a request, you receive a job ID immediately. Most phone lookups complete within a few seconds. Poll the monitor endpoint to check status and retrieve the completed response. This approach allows your system to continue processing without waiting on each lookup.
The risk score is a float value between 0 and 1. A score closer to 0 indicates lower risk signals, while a score closer to 1 indicates higher risk signals based on fraud patterns, abuse history, and network-level indicators. The score is a decision-support signal — your team sets the thresholds for what constitutes high, medium, or low risk in your specific context.
Yes. The line_type field returns the network category for the number, including mobile, landline, voip, prepaid, and tollfree. VoIP and prepaid numbers are commonly associated with higher fraud risk and can be used as one signal in your onboarding or transaction review workflow.
Data handling is governed by the ClearCheck Data Privacy Policy and Data Processing Addendum. Customers with specific data retention requirements should review the DPA or contact sales to discuss enterprise data handling options. All API calls are transmitted over HTTPS with TLS encryption.
Yes. The Phone Lookup API supports international phone numbers in E.164 format across all major regions including North America, Europe, Asia-Pacific, Latin America, and the Middle East. Coverage depth varies by region — contact sales for information on coverage in specific markets.