The VK check indicates whether a VK account is associated with a Russian phone number. It runs in real time and in bulk jobs, and answers registered: true, false or null (unknown) with the time of the check. Numbers outside Russia return unsupported_country and are not charged. No profile data is ever returned.
What does the VK check tell you?
It tells you whether a Russian mobile number is linked to an account on VK, the Russian social network run by VK Company. VK uses the phone number as the main sign-in identifier through VK ID, a single account used across several of the company's services. A number with an associated account has usually been confirmed with a code on VK.
registered: true: a VK account is associated with the number.registered: false: a conclusive "no".registered: null: no conclusive answer. Not charged.status: unsupported_country: the number is not Russian. Not charged.
Here the phone number is how people sign in, not an optional extra added for recovery. That makes a true answer on VK more informative than on platforms where most people register with an e-mail address.
Who uses it, and why?
The VK check suits businesses that serve customers in Russia and need a quick signal on a Russian number.
- Sign-up and OTP protection. In a live sign-up, a number with a VK account is more likely to be a person's everyday mobile number than a number bought for a single registration. See OTP and sign-up fraud.
- Channel choice for expected messages. Combine with Telegram and MAX to see which messengers a consenting customer is likely to use.
- Lead verification for Russian consumer leads.
For e-mail addresses on the same market, see the Mail.ru and Yandex e-mail checks.
What do you get back?
Each number gets one result under checks["vk.registered"], with no extra attributes.
| Field | Type | Meaning |
|---|---|---|
registered | boolean or null | true account associated, false none, null unknown |
status | enum | completed, pending, unknown, unsupported_country or failed |
confidence / confidence_score | enum / 0–1 | How sure the answer is |
checked_at | timestamp | When the answer was obtained |
cached / age_seconds | boolean / integer | Served from your account's cache, and its age |
billed | boolean | Whether this check was charged |
reason | string or null | Why an answer is not conclusive, e.g. UNSUPPORTED_COUNTRY |
How is it billed?
You pay per number checked, and only for conclusive answers. You're not charged for inconclusive results (unknown, unsupported country, timeout, invalid, duplicate). Real-time and bulk checks are priced separately. See pricing. Cache hits inside the freshness window are free, and max_age: 0 forces a fresh, billed check.
What are the limits?
- Real time (
POST /v1/lookup, up to 100 identifiers) and bulk jobs (POST /v1/jobs, up to 50,000 per job). - Russia only. The +7 country code is shared with Kazakhstan, so numbers are checked against the Russian numbering plan, not just the prefix.
- Up to 20 checks per request. Numbers × checks is capped at 2,000 per lookup and 100,000 per job.
- Requests that look like sequential number ranges or generated e-mail lists are rejected.
- A daily cap per account applies (
GET /v1/limits).
How do I use it responsibly?
Check only numbers you have a lawful basis to process under the laws that apply to you and to the people concerned. Use results for fraud prevention and for choosing a channel for messages people expect. Don't use them for profiling or unsolicited contact, which our acceptable use policy forbids. People can object at /opt-out.
Example request
With a test key, +447700900001 answers "registered" (test numbers bypass the country limit). See test mode.
curl https://api.mobilevalidate.com/v1/lookup \
-H "Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym" \
-H "Content-Type: application/json" \
-d '{"numbers":["+447700900001"],"checks":["vk"]}'// 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.lookup({
numbers: ["+447700900001"],
checks: ["vk"],
});
if (error) console.error(error.code, error.message);
else console.dir(data.results, { 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/lookup", {
method: "POST",
headers: {
Authorization: "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym",
"Content-Type": "application/json",
},
body: JSON.stringify({ numbers: ["+447700900001"], checks: ["vk"] }),
});
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.lookup(numbers=["+447700900001"], checks=["vk"])
print(result)<?php
$ch = curl_init('https://api.mobilevalidate.com/v1/lookup');
curl_setopt_array($ch, [
CURLOPT_POST => true,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
'Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym',
'Content-Type: application/json',
],
CURLOPT_POSTFIELDS => json_encode([
'numbers' => ['+447700900001'],
'checks' => ['vk'],
]),
]);
$response = curl_exec($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"],"checks":["vk"]}`)
req, err := http.NewRequest("POST", "https://api.mobilevalidate.com/v1/lookup", 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/lookup")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym"
req["Content-Type"] = "application/json"
req.body = JSON.generate({
"numbers" => ["+447700900001"],
"checks" => ["vk"]
})
res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |http| http.request(req) }
puts res.code, res.bodyRuns as pasted with the public sandbox key, which answers the test values only. In the SDKs, omit the key to use MOBILEVALIDATE_API_KEY.
Response (excerpt, test mode: the first item of results):
{
"kind": "phone",
"input": "+447700900001",
"e164": "+447700900001",
"country": "GB",
"number_status": "valid",
"checks": {
"vk.registered": {
"service": "vk.registered",
"status": "completed",
"registered": true,
"attributes": null,
"confidence": "high",
"confidence_score": 0.99,
"checked_at": "2026-09-25T14:25:31.077Z",
"cached": false,
"age_seconds": 0,
"billed": false,
"reason": null,
"poll_after_ms": null
}
},
"test": true
}Try it now
Realtime lookup via POST /v1/lookup. Every example runs as pasted: it uses the public sandbox key, which answers the test values for free. In the SDKs, omit the key to use MOBILEVALIDATE_API_KEY.
curl https://api.mobilevalidate.com/v1/lookup \
-H "Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym" \
-H "Content-Type: application/json" \
-d '{"numbers":["+447700900001"],"checks":["vk.registered"]}'// 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.lookup({
numbers: ["+447700900001"],
checks: ["vk.registered"],
});
if (error) console.error(error.code, error.message);
else console.dir(data.results, { 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/lookup", {
method: "POST",
headers: {
Authorization: "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym",
"Content-Type": "application/json",
},
body: JSON.stringify({
numbers: ["+447700900001"],
checks: ["vk.registered"],
}),
});
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.lookup(numbers=["+447700900001"], checks=["vk.registered"])
print(result)<?php
$ch = curl_init('https://api.mobilevalidate.com/v1/lookup');
curl_setopt_array($ch, [
CURLOPT_POST => true,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
'Authorization: Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym',
'Content-Type: application/json',
],
CURLOPT_POSTFIELDS => json_encode([
'numbers' => ['+447700900001'],
'checks' => ['vk.registered'],
]),
]);
$response = curl_exec($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"],"checks":["vk.registered"]}`)
req, err := http.NewRequest("POST", "https://api.mobilevalidate.com/v1/lookup", 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/lookup")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym"
req["Content-Type"] = "application/json"
req.body = JSON.generate({
"numbers" => ["+447700900001"],
"checks" => ["vk.registered"]
})
res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |http| http.request(req) }
puts res.code, res.body// .mcp.json (Claude Code), ~/.cursor/mcp.json (Cursor) or .vscode/mcp.json ("servers" instead of "mcpServers")
{
"mcpServers": {
"mobilevalidate": {
"type": "http",
"url": "https://mcp.mobilevalidate.com/mcp",
"headers": { "Authorization": "Bearer ${MOBILEVALIDATE_API_KEY}" }
}
}
}
// Then ask your agent, e.g.:
// "Check +447700900001 with vk.registered" → tool: lookup_numbersThe hosted MCP server is live for customers with an agent key (mv_agent_…) or a test key. Or run it locally with npx -y @mobilevalidate/mcp.
Real test-mode result for this check
{
"service": "vk.registered",
"status": "completed",
"registered": true,
"attributes": null,
"confidence": "high",
"confidence_score": 0.99,
"checked_at": "2026-09-25T14:25:28.979Z",
"cached": false,
"age_seconds": 0,
"billed": false,
"reason": null,
"poll_after_ms": null
}What you get
Fields of checks["vk.registered"], generated from the public service catalog.
| Field | Type | Meaning |
|---|---|---|
| registered | boolean | null | true = found, false = not found, null = unknown (not charged). |
| status | enum | completed, pending, unknown, unsupported_country or failed. |
| checked_at | timestamp | When the answer was obtained. |
Frequently asked questions
Which numbers does the VK check accept?
Russian numbers only. Numbers from other countries, including other +7 numbers that are not Russian, come back as unsupported_country and are not charged.
Why is the phone number a strong signal on VK?
VK signs people in with a phone number through its VK ID account, so an associated account usually means the number was verified with a code on VK. Treat it as a signal, not as identity proof.
Is the answer instant?
Usually. The VK check is available in real time on POST /v1/lookup and waits up to 10 seconds by default. Slower answers come back as pending.
Does the check return the VK profile?
No. It only indicates whether a VK account is associated with the number. Names, photos, profile pages and friends are never returned.
Can I test it without a Russian number?
Yes. With a test key the documented test numbers (+44 7700 900xxx) work for every service, including VK.

