> ## Documentation Index
> Fetch the complete documentation index at: https://developer.z-api.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Batch verification

> Batch check if numbers have WhatsApp accounts

## Overview

Unlike the previous method that individually validates if a number has WhatsApp through a GET request, this API offers batch verification.

<Info>
  Maximum of **50,000** validations per request.
</Info>

<Tip>
  Use this API for form validation. It is not recommended to use this API to verify the number's existence before sending a message, as Z-API already validates the number's existence for each message sent.
</Tip>

***

## Attributes

### Header

<ParamField path="instanceId" type="string" required>
  Your instance ID. Available in the Z-API panel under **Instances**.
</ParamField>

<ParamField path="token" type="string" required>
  Your Z-API instance token.
</ParamField>

### Body

<ParamField body="phones" type="array" required>
  List of phone numbers in DDI DDD NUMBER format. E.g.: 551199999999
</ParamField>

***

## Request Body

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "phones": ["554499999999", "554488888888"]
}
```

***

## Response

### 200

<ResponseField name="exists" type="boolean">
  Whether the number has WhatsApp
</ResponseField>

<ResponseField name="inputPhone" type="string">
  Number sent in the request
</ResponseField>

<ResponseField name="outputPhone" type="string">
  Formatted number per WhatsApp's response
</ResponseField>

<ResponseField name="lid" type="string">
  WhatsApp's unique private identifier (null if exists = false)
</ResponseField>

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
[
  {
    "exists": true,
    "inputPhone": "554499999999",
    "outputPhone": "554499999999",
    "lid": "999999999999999@lid"
  }
]
```

### 405

Make sure you are correctly sending the method specification, that is, verify that you sent POST or GET as specified at the beginning of this topic.

### 415

If you receive a 415 error, make sure to add the "Content-Type" header to your request, which in most cases is "application/json".