Validate Phone

VerifNow checks a phone number against its country’s numbering plan: the right length, and a prefix that is actually allocated. Valid numbers come back normalized to E.164, with the country and the kind of line they belong to.

Basic phone validation

Send the number with its country code, written with + or the 00 international prefix. Spaces, dashes and parentheses are fine.

POST https://api.verifnow.io/api/v1/validate/phone
X-API-KEY: your_api_key_here
Content-Type: application/json
 
{
  "value": "+33 6 12 34 56 78"
}

Example response

{
  "valid": true,
  "message": "Valid phone number",
  "normalizedValue": "+33612345678",
  "originalValue": "+33 6 12 34 56 78",
  "validationLevel": "STANDARD",
  "phoneDetails": {
    "country_code": "FR",
    "calling_code": 33,
    "line_type": "MOBILE",
    "international_format": "+33 6 12 34 56 78",
    "national_format": "06 12 34 56 78"
  }
}

Store normalizedValue. E.164 is the form SMS providers and telephony APIs expect, and it makes two spellings of the same number compare equal.

Why the country code is required

The request carries a single value. Without a country code, 06 12 34 56 78 is a French mobile, and a malformed number almost everywhere else. Guessing a default country would validate the wrong thing without telling you.

If your form collects the country separately, prepend its calling code before sending — or, better, use a phone input that produces E.164 directly.

{
  "valid": false,
  "message": "Phone number must include its country code, e.g. +33 6 12 34 56 78",
  "originalValue": "06 12 34 56 78",
  "validationLevel": "STANDARD"
}

phoneDetails

phoneDetails is also returned for an invalid number, as long as it could be read as international. Knowing the input was read as French but is one digit short lets you write a better error message than “invalid phone”:

{
  "valid": false,
  "message": "Phone number is too short for its country",
  "originalValue": "+33 6 12 34 56 7",
  "validationLevel": "STANDARD",
  "phoneDetails": {
    "country_code": "FR",
    "calling_code": 33
  }
}

line_type

A PREMIUM_RATE or VOIP number is still valid: true — it exists. line_type is how you decide to exclude one, rather than the API deciding for you.

Acceptance strategy

import { VerifNow } from '@verifnow/sdk';
 
const client = new VerifNow({ apiKey: process.env.VERIFNOW_API_KEY });
 
const result = await client.validatePhone(input);
 
if (!result.valid) {
  return reject(result.message); // the message is written to be shown to a user
}
 
const { lineType, countryCode } = result.phoneDetails;
 
if (lineType === 'PREMIUM_RATE') {
  return reject('Please enter a number we can call at a normal rate.');
}
 
if (requiresSms && lineType !== 'MOBILE' && lineType !== 'FIXED_LINE_OR_MOBILE') {
  return reject('Please enter a mobile number so we can text you a code.');
}
 
return accept({ phone: result.normalizedValue, country: countryCode });

curl -X POST https://api.verifnow.io/api/v1/validate/phone \
  -H "X-API-KEY: $VERIFNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"value": "+33 6 12 34 56 78"}'

Phone checks are the same on every plan. Validation depth by plan only changes email signals.

Common errors

See Error Handling for transport-level failures and status codes.

Next steps

• Validating a B2B signup form — phone, work email and VAT together
• Validate Email
• Validate VAT