> ## Documentation Index
> Fetch the complete documentation index at: https://docs.iterapay.com/llms.txt
> Use this file to discover all available pages before exploring further.

# POST /ipAddress/{merchantID} — Set IP address restriction

> Create or update the IP address whitelist for a merchant. Only requests originating from the configured IP will be accepted when using API key authentication.

Use this endpoint to restrict API key usage to a specific IP address. When an IP address restriction is set, any API key request that does not originate from the configured address will be rejected, providing an additional layer of security for your integration.

<Info>
  IP address restrictions apply to API key authentication only. Bearer token requests are not affected by this setting.
</Info>

<Note>
  This endpoint requires Bearer token authentication. API key authentication is not accepted.
</Note>

## Path parameters

<ParamField path="merchantID" type="string" required>
  The UUID of the merchant for which to configure the IP address restriction.
</ParamField>

## Request body

<ParamField body="ipAddress" type="string" required>
  The IPv4 address to allowlist. Only requests from this address will be accepted when authenticating with an API key for this merchant.
</ParamField>

## Response

Returns `204 No Content` on success. No response body is returned.

<RequestExample>
  ```bash cURL theme={null}
  curl --request POST \
    --url https://api.iterapay.com/ipAddress/b0fcc813-a7ce-4bbc-932f-dbef6f59ca7f \
    --header 'Authorization: Bearer <token>' \
    --header 'Content-Type: application/json' \
    --data '{
      "ipAddress": "203.0.113.42"
    }'
  ```
</RequestExample>

<ResponseExample>
  ```text 204 theme={null}
  (no content)
  ```
</ResponseExample>