Should I call the number in this message?

Purpose

Paste a text, email or letter that asks you to call a number and check first whether it’s premium-rate, from another country or a satellite network.

Requirements

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

Many scams don’t include a link: they ask you to call (“call to cancel the charge”, “contact our fraud department”). Paste the message and we check every number before you dial.

How to use it

1. 1

   Message with the number

2. 2

   Check numbers

3. 3

   Read the available fields alongside their limitations. An empty result does not prove safety or identify a person.

Synthetic example

Your account is locked, call +44 1632 960123

Interpret the result

Don’t call this number: The message sends you to an expensive number or one from a typical scam origin. If it claims to be from a company or an authority, find their number on their official website, your contract or your card, and call that one.

Check before you call: It’s a number from another country or a shared-cost number: calling may cost more than usual, and a message asking you to call a foreign number deserves suspicion.

No expensive number and no suspicious origin: That doesn’t prove the message is genuine: scammers also use ordinary and toll-free numbers. If it claims to be from a company, call the number on its official website, not the one in the message.

Limitations

Troubleshooting

We didn’t find a valid phone number in the text. If it’s incomplete or mistyped, search for it on NoCall exactly as it appears.

The text is too long: paste 2,000 characters at most.

Use with the API

Every valid phone number in a pasted SMS, email or letter (up to 10), with its type, what calling it costs, whether it is foreign and its wangiri verdict, plus signals such as a request to call or a forwarding code. Nothing is stored.

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/callback-number
POST https://api.nocall.io/v2/tools  {"tool":"callback-number","text":"Your account is locked. Call us now on 0909 879 0000 or +216 71 123 456","country":"GB"}

REQUEST_ID="$(uuidgen)" && [ -n "$REQUEST_ID" ] &&
curl --request POST 'https://api.nocall.io/v2/callback-number' \
  --header "Authorization: Bearer $NOCALL_API_KEY" \
  --header 'Content-Type: application/json' \
  --header "Idempotency-Key: $REQUEST_ID" \
  --data '{"text":"Your account is locked. Call us now on 0909 879 0000 or +216 71 123 456","country":"GB"}'

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/callback-number',
    method='POST',
    data=json.dumps({'text': 'Your account is locked. Call us now on 0909 879 0000 or +216 71 123 456', 'country': 'GB'}).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/callback-number', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer ' + apiKey,
    'Content-Type': 'application/json',
    'Idempotency-Key': requestId,
  },
  body: JSON.stringify({ text: 'Your account is locked. Call us now on 0909 879 0000 or +216 71 123 456', country: 'GB' }),
});
const result = await response.json();
if (!response.ok) throw new Error(result.error?.code ?? 'request_failed');
console.log(result.data.result, result.meta.unitsCharged);

{
  "data": {
    "tool": "callback-number",
    "result": {
      "numbers": [
        {
          "e164": "+449098790000",
          "country": "GB",
          "type": "premium_rate",
          "category": "premium",
          "risk": "high",
          "international": false,
          "wangiri": null
        },
        {
          "e164": "+21671123456",
          "country": "TN",
          "type": "fixed_line",
          "category": "wangiri",
          "risk": "high",
          "international": true,
          "wangiri": "listed"
        }
      ],
      "signals": [
        "asks_to_call",
        "premium_number",
        "wangiri_country",
        "international_number"
      ],
      "attention": true
    }
  },
  "meta": {
    "requestId": "req_example",
    "unitsCharged": 1,
    "usage": {
      "periodStart": "2026-10-01",
      "unitLimit": 20,
      "unitsUsed": 3,
      "unitsRemaining": 17
    }
  }
}

• API reference ↗

Frequently asked questions

Related guides

• Is it a premium-rate number?
• Wangiri check: is this missed call a scam?
• What is smishing?