# Customize System Prompt

System prompts are the built-in audio messages your phone system plays to callers, such as "the person you are calling is not available" or queue and voicemail announcements. Cloud Voice ships with a selection of ready-made [online system prompts](/pbx/administrator-guide/change-system-prompt/) you can activate at any time. When none of those fit your brand, language, or wording needs, you can supply a prompt recorded specifically for your organization and set it as the system default.

:::note
Custom prompts cannot be recorded inside the web portal. IZT Support produces the recording for you, packages it, and returns a file you upload to your PBX (Private Branch Exchange, the phone system that routes your calls). The steps below cover the upload and activation only.
:::

:::tip
Before commissioning a custom recording, browse the ready-made online prompts first. If one already covers your language and wording, you can activate it immediately and skip the recording request entirely.
:::

## Before you begin

- Contact IZT Support to arrange the recording of your custom prompt.
- Make sure the prompt file you receive meets these requirements:
  - **File type**: `.tar`
  - **File name**: no special characters
  - **File size**: 100 MB or less

:::caution
The upload accepts only a `.tar` file with a plain (no special characters) file name that is 100 MB or smaller. A file that fails any of these three rules will be rejected. Confirm the file matches all three before you start.
:::

## Upload and apply a custom prompt

1. Sign in to the PBX web portal and open **PBX Settings > Voice Prompt > System Prompt**.
2. Add the custom prompt file:
   1. Click **Upload System Prompts**.
   2. In the dialog, choose the `.tar` file from your computer and click **Open**.

   Once the upload finishes, the file appears in the **System Prompt** list.
3. In the **Default** column, mark your uploaded prompt as the default.

   :::note
   Only one prompt can be the default at a time. Setting your uploaded prompt as default replaces whichever prompt was active before, so the system stops using the old one right away.
   :::
4. Click **Save**, then **Apply**.

   :::caution
   Your change is not live until you click **Apply**. If you click **Save** but skip **Apply**, the new default is stored but callers will still hear the previous prompt.
   :::

The selected prompt is now live and used by the system.