Phone Validation API

Structurally validate and normalize phone numbers to E.164. Get line type, location hints, timezones, carrier details, and dialability flags where available. Ideal for registration forms and contact cleanup — not live line verification.

API endpoint
GET https://phonevalidation.cleariflow.com/v1/?api_key=YOUR_API_KEY&country=US&phone=%2B14155552671

Try it now

Test the API with live data

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API benefits

E.164 Standard

Normalize valid numbers to E.164 and national formats with structural format checks.

Global Coverage

Support for phone numbers from over 240 countries and territories worldwide.

Location & Timezones

Location hints and timezone identifiers when available (most often US/CA).

Carrier Details

Carrier names and safe display names when available — mainly US/CA. Not subscriber verification.

Number Type Detection

Classify landline, mobile, toll-free, VoIP, and other line types when valid.

Real-time Validation

Instant structural phone validation with sub-200ms response times.

Key features

  • E.164 format validation
  • 240+ countries supported
  • Structural format validation
  • Lenient possible-number check
  • Invalid reason codes for failed parses
  • Carrier name when available (mainly US/CA)
  • Safe carrier name for UI display
  • Number type classification
  • Location hints (mainly US/CA)
  • Timezone identifiers per number
  • Geographic region association
  • International dialability flag
  • International format conversion
  • Local format conversion
  • Mobile vs fixed-line detection
  • VoIP number identification
  • JSON response format

Quick start guide

1. Get your API key

Sign up for free and get instant access to your API key.

2. Make your first request

cURL
curl -X GET \
  "https://phonevalidation.cleariflow.com/v1/" \
  ?api_key=YOUR_API_KEY \
  &phone=%2B14155552671 \
  &country=US

3. Handle the response

JSON
{
  "carrier": "",
  "carrier_display": "",
  "country": {
    "code": "US",
    "name": "United States",
    "prefix": "+1"
  },
  "format": {
    "international": "+14155552671",
    "local": "(415) 555-2671"
  },
  "geographical": true,
  "internationally_dialable": true,
  "location": "San Francisco, CA",
  "phone": "14155552671",
  "possible": true,
  "timezones": [
    "America/Los_Angeles"
  ],
  "type": "Landline_or_Mobile",
  "valid": true
}