> ## 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.

# Block / Unblock contact

> Block or unblock a contact on WhatsApp

## Overview

This method is responsible for blocking or unblocking a contact.

***

## 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>

### Required

<ParamField body="phone" type="string" required>
  Contact phone number
</ParamField>

<ParamField body="action" type="string" required>
  Action to execute: `block` or `unblock`
</ParamField>

***

## Request Body

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "phone": "5544999999999",
  "action": "block"
}
```

***

## Response

### 200

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "value": true
}
```

### 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".