# Restrict Outbound Calls for an Extension

Toll fraud is an ongoing threat across the telecom industry: an attacker who gains access to your phone system can rack up costly calls through a compromised account. One way to limit that risk is to turn off outbound calling for any extension that does not need it, so a stolen credential cannot be used to dial out.

## Disable outbound calling

1. Sign in to the Cloud Voice management portal and go to **Extension and Trunk > Extension**, then open the extension you want to lock down for editing.
2. Open the **Security** tab.
3. Under **Call Restrictions**, tick the **Disable Outbound Calls** checkbox.
4. Select **Save**, then **Apply**.

:::caution
The restriction takes effect the moment you select **Apply**. Confirm you are editing the intended extension first: this blocks every outbound call the extension can place, not just calls to certain numbers.
:::

![Security tab showing the Disable Outbound Calls option enabled under Call Restrictions](/images/pbx/disable-outbound-calls.png)

## What changes

- The extension can no longer place outbound calls, even when it is still listed in an outbound route.
- In the extension list, a warning marker ![Outbound-calls-restricted indicator](/images/pbx/trunk-error-2.png) appears beside the extension so you can see the restriction at a glance.

:::note
Emergency calls, such as 911, remain available and are never blocked by this setting.
:::

:::tip
To lift the restriction later, select the edit icon ![Edit extension](/images/pbx/edit.png) for the extension, return to the **Security** tab, and clear the **Disable Outbound Calls** checkbox under **Call Restrictions**.
:::