Check if a phone number is registered on Viber

The Viber check answers whether a phone number has a Viber account. It returns registered: true, false or null (unknown) with the time of the check. It runs in bulk jobs, for numbers from any country (real-time requests are paused for now). Nothing is sent to the number, and no name, photo or online status is returned.

What does the Viber check tell you?

It tells you whether a Viber account is associated with the number. Viber identifies users by their phone number: you install the app on a phone, confirm the number, and your contacts see you under that number. There is no username layer on top, so the number is the account.

• registered: true: a Viber account exists for the number.
• registered: false: a conclusive answer that there is no account.
• registered: null: no conclusive answer; status and reason explain why. It is not charged.

Viber launched in 2010 and has been owned by the Japanese company Rakuten since 2014 (Rakuten press release, February 2014). Accounts can outlive the phone they were created on, and numbers get recycled by carriers, so read registered together with checked_at, and keep max_age short where freshness matters.

Who uses it, and why?

Viber's footprint is regional. In several countries of Eastern Europe, the Balkans, the Middle East and Southeast Asia it is one of the most-used messengers. Elsewhere it plays a smaller part.

• Cheaper delivery of expected messages. Viber offers paid business messaging with a branded sender, which many companies in Viber-heavy markets use for transactional messages and codes, falling back to SMS when the person has no account. Checking first keeps undeliverable Viber attempts, and the delay they cause, out of the flow. See SMS cost reduction.
• Channel order per market. Teams operating across countries check WhatsApp, Telegram and Viber in one request and choose the channel the customer opted into and actually has.
• Deliverability signal. A Viber account shows the number passed a phone-based activation at some point. Together with a carrier lookup, this helps separate live mobile numbers from typos and landlines.

What do you get back?

One result per number in checks["viber.registered"]; no extra attributes.

How is it billed?

Per number, only for conclusive answers. You're not charged for inconclusive results (unknown, unsupported country, timeout, invalid, duplicate). You pay the bulk price, and POST /v1/jobs/estimate shows the maximum cost before you start. See pricing.

Within the freshness window a repeat check can be answered from your account's cache, free of charge (cached: true, billed: false). Use max_age: 0 for a fresh, billed answer and max_cost to cap a request.

What are the limits?

The Viber check runs in bulk jobs (POST /v1/jobs, up to 50,000 numbers and e-mails). Real-time requests (POST /v1/lookup) are paused while our real-time route is unreliable; they return 403 service_disabled with a pointer to bulk jobs. All countries are accepted.

• Up to 20 checks per request, and numbers × checks up to 2,000 per lookup or 100,000 per job.
• Requests that look like sequential number ranges or generated e-mail lists are rejected (suspected_enumeration).
• Each account has a daily number cap (GET /v1/limits).
• Numbers written without a country code need default_country to be read correctly.

How do I use it responsibly?

Use the check to decide how to reach customers who asked to hear from you, not to find new people to message. Viber's business messaging requires approved senders and opted-in recipients, and our acceptable use policy forbids unsolicited bulk messaging and scanning number ranges. Keep a lawful basis for every list you check. People whose numbers were checked can object via the opt-out form.

Example request

Create a job with test numbers, then read its results. Test keys are free and never reach a real network; +447700900001 answers "registered". See test mode and bulk jobs.

curl https://api.mobilevalidate.com/v1/jobs \
  -H "Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym" \
  -H "Content-Type: application/json" \
  -d '{"numbers":["+447700900001","+447700900002","+447700900003"],"checks":["viber"]}'

// npm install mobilevalidate · Node.js 20+ · save as check.mjs and run: node check.mjs
import { MobileValidate } from "mobilevalidate";

// Omit apiKey to read MOBILEVALIDATE_API_KEY from the environment.
const mv = new MobileValidate({ apiKey: "mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym" });
const { data, error } = await mv.jobs.create({
  numbers: ["+447700900001", "+447700900002", "+447700900003"],
  checks: ["viber"],
});
if (error) console.error(error.code, error.message);
else console.dir(data, { depth: null });

// Node.js 18+, Deno, Bun or the browser console (ES module: save as .mjs or use "type": "module").
const res = await fetch("https://api.mobilevalidate.com/v1/jobs", {
  method: "POST",
  headers: {
    Authorization: "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    numbers: ["+447700900001", "+447700900002", "+447700900003"],
    checks: ["viber"],
  }),
});
console.log(res.status, res.headers.get("x-request-id"));
console.dir(await res.json(), { depth: null });

# pip install mobilevalidate-sdk
from mobilevalidate import MobileValidate

# Omit api_key to read MOBILEVALIDATE_API_KEY from the environment.
mv = MobileValidate(api_key="mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym")
result = mv.jobs.create(
    numbers=["+447700900001", "+447700900002", "+447700900003"],
    checks=["viber"],
)
print(result)

<?php
$ch = curl_init('https://api.mobilevalidate.com/v1/jobs');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym',
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode([
        'numbers' => ['+447700900001', '+447700900002', '+447700900003'],
        'checks' => ['viber'],
    ]),
]);
$response = curl_exec($ch);
echo curl_getinfo($ch, CURLINFO_RESPONSE_CODE), PHP_EOL, $response, PHP_EOL;

package main

import (
	"fmt"
	"io"
	"net/http"
	"strings"
)

func main() {
	body := strings.NewReader(`{"numbers":["+447700900001","+447700900002","+447700900003"],"checks":["viber"]}`)
	req, err := http.NewRequest("POST", "https://api.mobilevalidate.com/v1/jobs", body)
	if err != nil {
		panic(err)
	}
	req.Header.Set("Authorization", "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym")
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

require "net/http"
require "json"

uri = URI("https://api.mobilevalidate.com/v1/jobs")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym"
req["Content-Type"] = "application/json"
req.body = JSON.generate({
  "numbers" => ["+447700900001", "+447700900002", "+447700900003"],
  "checks" => ["viber"]
})

res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |http| http.request(req) }
puts res.code, res.body

Result row (excerpt, test mode: the first item of data from GET /v1/jobs/{id}/results):

{
  "kind": "phone",
  "input": "+44770*****01",
  "e164": "+447700900001",
  "country": "GB",
  "number_status": "valid",
  "checks": {
    "viber.registered": {
      "service": "viber.registered",
      "status": "completed",
      "registered": true,
      "attributes": null,
      "confidence": "high",
      "confidence_score": 0.99,
      "checked_at": "2026-09-25T14:25:29.589Z",
      "cached": false,
      "age_seconds": 0,
      "billed": false,
      "reason": null,
      "poll_after_ms": null
    }
  },
  "test": true
}