Asked to dial a code?

Purpose

Type the code you’ve been asked to dial (such as **21*…# or *401*…) to find out whether it forwards your calls to someone else, how to undo it and why it’s a scam.

Requirements

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

If someone calling from “your carrier”, “the courier” or “WhatsApp support” asks you to dial a code with stars and hashes, type it here first. Many of those codes forward your calls to the caller, who then receives your voice verification codes.

How to use it

1. 1

   The code you’re asked to dial

2. 2

   Check

3. 3

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

Synthetic example

**21*+44 1632 960123#

Interpret the result

Call forwarding: This code changes where your calls go.

Call barring: This code blocks incoming or outgoing calls on your line.

Call waiting: This code turns call waiting on or off, or checks it.

Show or hide your number: This code decides whether the person you call sees your number.

Show your phone’s IMEI: This code shows your phone’s serial number (IMEI) on screen. It changes nothing, but don’t read it out to strangers.

Change the call barring password: This code changes the password that protects call barring on your line.

USSD banking: This code opens a banking or payment menu from your carrier. If someone walks you through that menu, they can make you send money.

A carrier service: It’s a service code of your carrier, for example to check your balance. Every carrier has its own: check its website or app.

It’s a phone number, not a code: It has no stars or hashes: it’s an ordinary number.

We don’t recognise this code: It doesn’t match any standard code. Don’t dial it if a stranger gave it to you.

Limitations

To see whether any forwarding is on, dial *#21# and press call.

Troubleshooting

Type the code exactly as you were given it, with its * and #.

The code is too long: type 64 characters at most.

Use with the API

What a code someone asks you to dial does: call forwarding (and where to), barring, call waiting, caller ID or a carrier service, with its risk and the code that undoes it. Barring passwords are masked.

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/dial-code
POST https://api.nocall.io/v2/tools  {"tool":"dial-code","code":"**21*+34600000000#","country":"ES"}

REQUEST_ID="$(uuidgen)" && [ -n "$REQUEST_ID" ] &&
curl --request POST 'https://api.nocall.io/v2/dial-code' \
  --header "Authorization: Bearer $NOCALL_API_KEY" \
  --header 'Content-Type: application/json' \
  --header "Idempotency-Key: $REQUEST_ID" \
  --data '{"code":"**21*+34600000000#","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/dial-code',
    method='POST',
    data=json.dumps({'code': '**21*+34600000000#', '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/dial-code', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer ' + apiKey,
    'Content-Type': 'application/json',
    'Idempotency-Key': requestId,
  },
  body: JSON.stringify({ code: '**21*+34600000000#', 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);

{
  "data": {
    "tool": "dial-code",
    "result": {
      "code": "**21*+34600000000#",
      "kind": "call_forwarding",
      "action": "register",
      "service": "unconditional",
      "forwardsTo": "+34600000000",
      "calls": null,
      "risk": "high",
      "undo": "##002#",
      "operator": null
    }
  },
  "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 this call a scam?
• Asked for a code sent by SMS?
• Wangiri check: is this missed call a scam?