# Enable or Disable Call Emergency via Mobile Number

The Cloud Voice App can place emergency calls two ways. Your phone system uses a PBX (Private Branch Exchange, the business phone platform that manages your extensions and outbound lines). By default an emergency call would leave over a PBX trunk (the connection between your phone system and the outside phone network). With **Call Emergency via Mobile Number** turned on, dialing an emergency number in the app instead hands the call to your phone's built-in cellular dialer, so it goes out over your mobile carrier rather than the PBX. Because the call then originates from your handset, emergency services receive your carrier's location and callback details directly.

This page shows how to turn the feature on or off from the app.

:::danger
This setting decides how your emergency calls (for example 911) reach emergency services, which affects the location and callback number they see. Pick the option that gives responders the most accurate location for where you actually are, and confirm the behavior with your system administrator. Never dial a live emergency number just to test routing.
:::

## Before you begin

- Your system administrator must have configured emergency numbers on the PBX. Without them, the app has no numbers to treat as emergency calls.
- Your Cloud Voice App must meet the minimum version:
  - **iOS**: 5.5.9 or later
  - **Android**: 5.5.8 or later

:::note
The app only recognizes a dialed number as an emergency call if it matches one of the emergency numbers your administrator set on the PBX. If you are unsure which numbers are configured, ask your administrator before relying on this feature.
:::

## Turn on Call Emergency via Mobile Number

1. On the **Calls** page, tap your account in the top-left corner.
2. Go to **Settings > Advanced**.
3. Enable the **Call Emergency via Mobile Number** switch.

![Advanced settings screen with the Call Emergency via Mobile Number toggle switched on](/images/pbx/enable-call-emergency-via-mobile-number.png)

With the switch on, dialing an emergency number in the app opens your phone's native cellular dialer. Tap the call button there, and the call is placed over your mobile number.

:::tip
This is the recommended setting for most mobile users. Routing through your carrier means emergency services receive the location and callback number tied to your mobile phone, rather than a fixed address registered against the PBX.
:::

:::caution
The call is not placed automatically. After the app hands off to the cellular dialer, you still have to press the call button on your phone to actually connect the emergency call.
:::

## Turn off Call Emergency via Mobile Number

1. On the **Calls** page, tap your account in the top-left corner.
2. Go to **Settings > Advanced**.
3. Disable the **Call Emergency via Mobile Number** switch.

![Advanced settings screen with the Call Emergency via Mobile Number toggle switched off](/images/pbx/disable-call-emergency-via-phone-number.png)

With the switch off, dialing an emergency number in the app places the call through the PBX instead of your cellular carrier.

:::caution
When calls route through the PBX, the location that reaches emergency services depends on how emergency calling is configured on the phone system, not on where your handset happens to be. Only choose this option if your administrator has confirmed the PBX sends an accurate location for your extension.
:::