Calls & numbers

Phone number formats

API · Pro2026-10-28

Coverage: Areas come from the official numbering plan of each edition’s country. Spain lists a province for every landline range; many other countries list their area codes and cities. Mobile numbers have no area in any country, and a few countries do not publish a plan we can read yet: there we only show the type of line.

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On this page

Purpose

Check whether a phone number is valid, whether it is a mobile, landline, freephone or premium number, and see it in E.164, national and international format.

Requirements

Anyone can read these guides, no account needed. Some tools require Pro, as indicated in each guide.

Enter the full number with its international code. For a national number, first check the edition country or country selector.

How to use it

Phone number formats
Enter the full number with its international code. For a national number, first check the edition country or country selector.
Check
E.164 · Without calling code · International format

Synthetic example

Invented example, not a real lookup. Do not call or open its links.

+44 1632 960123

Interpret the result

It is the international standard for writing a number: a plus sign, the country calling code and the national number, with no spaces or leading zero. Apps and phone systems use it to store numbers.

Limitations

Formats and supported calling codes only. They do not prove a number’s location, owner or active status. Some codes are shared.

Troubleshooting

If the input is invalid, check its format and country. Retry connection errors; respect the waiting period when a limit is reached.

Invalid phone number

The security check or API connection did not respond in time. Try again in a few seconds.

Use with the API

Needs an API key and credits. Each completed call costs 1 credit, even when there is no data. An active Pro account includes 20 credits per UTC calendar month, shared by every API route and spent first; unused monthly credits do not roll over. Credits bought on your account page work without Pro and never expire.

Errors are never charged: 401 invalid_api_key (missing or invalid key), 403 pro_required (no Pro credits and no purchased credits), 422 invalid input, 429 quota_exceeded (no credits left), rate_limit_exceeded or ai_busy (the AI of sms-check is at capacity), 503 tool_warming (the data is still being prepared) or tool or provider unavailable. After a 429 or 503, retry once the seconds in the Retry-After header have passed.

E.164, national and international formats, calling code, country and validity from the numbering plan. A possible but unallocated number returns valid=false.

Send the JSON body to the tool's own route, or to POST /v2/tools with the tool field added. Both routes return the same result.

POST https://api.nocall.io/v2/phone-formats
POST https://api.nocall.io/v2/tools  {"tool":"phone-formats","phone":"+34912345678","country":"ES"}

Parameters

Name	Type	Required	Description
phone	string (1–40)	Yes	Phone number in E.164 (+34…) or national format.
country	string (enum, 56)	No (default: "ES")	Two-letter country code, for example ES or US, used for national input and for the country's data.

REQUEST_ID="$(uuidgen)" && [ -n "$REQUEST_ID" ] &&
curl --request POST 'https://api.nocall.io/v2/phone-formats' \
  --header "Authorization: Bearer $NOCALL_API_KEY" \
  --header 'Content-Type: application/json' \
  --header "Idempotency-Key: $REQUEST_ID" \
  --data '{"phone":"+34912345678","country":"ES"}'

import json
import os
import urllib.request
import uuid

api_key = os.environ.get('NOCALL_API_KEY')
if not api_key:
    raise SystemExit('Set NOCALL_API_KEY')

request = urllib.request.Request(
    'https://api.nocall.io/v2/phone-formats',
    method='POST',
    data=json.dumps({'phone': '+34912345678', 'country': 'ES'}).encode(),
    headers={
        'Authorization': 'Bearer ' + api_key,
        'Content-Type': 'application/json',
        'Idempotency-Key': str(uuid.uuid4()),
    },
)
with urllib.request.urlopen(request, timeout=30) as response:
    result = json.load(response)
print(result['data']['result'], result['meta']['unitsCharged'])

import { randomUUID } from 'node:crypto';

const requestId = randomUUID();
const apiKey = process.env.NOCALL_API_KEY;
if (!apiKey) throw new Error('Set NOCALL_API_KEY');

const response = await fetch('https://api.nocall.io/v2/phone-formats', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer ' + apiKey,
    'Content-Type': 'application/json',
    'Idempotency-Key': requestId,
  },
  body: JSON.stringify({ phone: '+34912345678', country: 'ES' }),
});
const result = await response.json();
if (!response.ok) throw new Error(result.error?.code ?? 'request_failed');
console.log(result.data.result, result.meta.unitsCharged);

Example response (200)

This is the documented example from the API reference. Lookups use a fictional number, and aggregates and AI answers show the shape of the result, not live data.

{
  "data": {
    "tool": "phone-formats",
    "result": {
      "e164": "+34912345678",
      "national": "912 34 56 78",
      "international": "+34 912 34 56 78",
      "callingCode": "34",
      "country": "ES",
      "valid": true
    }
  },
  "meta": {
    "requestId": "req_example",
    "unitsCharged": 1,
    "usage": {
      "periodStart": "2026-10-01",
      "unitLimit": 20,
      "unitsUsed": 3,
      "unitsRemaining": 17
    }
  }
}

Result fields (data.result)

Field	Type	Description
e164	string	The number in E.164 format, or null when it cannot be formatted.
national	string	The number in its country's national format.
international	string	The number in international format.
callingCode	string	Calling code of the number's country, or null when it is unknown.
country	string \| null	Country of the number (ISO code), or null when it cannot be determined.
valid	boolean	Whether the number is valid in the numbering plan. false is still a completed result.

API reference