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

# Overview

> Send a PDF as a fax from your Allo line, and read sent and received faxes

The Fax API sends a PDF as a fax from one of your Allo lines. Sent and received faxes then appear in your conversations, next to calls and SMS.

## What you need to send a fax

* **Fax on your account.** Faxing is not available on every account. Without it, the API returns `403` with code `FAX_NOT_AVAILABLE`: contact Allo support to get it enabled.
* **A line that supports fax.** The line must be a US or Canada local number. Toll-free numbers and sender IDs cannot send faxes.
* **Fax turned on for the line.** Turn on **Send and receive faxes** in the number settings in the Allo app. The API cannot change this setting.
* **Message credits.** Each faxed page uses [credits](https://help.withallo.com/en/billing/credits.md), the same balance that pays for SMS.

## How faxes appear in conversations

A fax is a conversation item of `type` `SMS` with `message_type` `FAX`. Its ID starts with `msg-`, like any message.

* `attachments` holds the faxed PDF, with a `download_url` valid for 30 minutes.
* `page_count` is the number of pages, or `null` while it is not known yet.
* `status` of a sent fax starts at `PENDING` and changes as the fax goes through.

To list only faxes, call [Search conversation items](https://help.withallo.com/en/v2/api-reference/conversations/search-conversation-items.md) with `type: "FAX"`. With `type: "SMS"`, faxes are included with the other messages.

> [card] [Send fax](https://help.withallo.com/en/v2/api-reference/fax/send-fax.md)
>
> Send a PDF as a fax from an Allo line


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