---title: Fax XMLexcerpt: ---import Tabs from @theme/Tabs;import TabItem from @theme/TabItem;Fax Compatibility XML is a set of actions defined in an XML document you can use to tell SignalWire what to do when you receive an incoming fax.## OverviewWhen a fax is sent to one of your SignalWire phone numbers, SignalWire looks up the Fax Compatibility XML document from the URL you configured, and reads the instructions you provided to determine what to do.Fax Compatibility XML allows you to control what SignalWire will do when you receive an incoming fax.## RequestSignalWire makes an HTTP request to your configured endpoint just like a regular web form submission (POST) or page load (GET). The request includes contextual information about the fax, allowing you to respond dynamically and fluidly to the fax to meet the needs of your application.You can configure the endpoint URL and HTTP Method in your phone number settings panel on your SignalWire dashboard, or via the REST API.## Request ParametersSignalWire sends the following parameters, as either URL query parameters or POST parameters, to your endpoint when it receives a fax:| Parameter | || --------------------------------------------------------: | ---------------------------------------------- || FaxSid string | A unique identifier for the fax. || AccountSid string | The account that the fax was sent from. || To string | The number or SIP URI the fax will be sent to. || From string | The number or SIP URI the fax was sent from. || ApiVersion string | The version of the SignalWire API. |## Responding to SignalWireAn example of a Compatibility XML document that receives an incoming fax:<receive>
instead of <Receive>
will result in an error.:::### StatusCallback when sending a faxWhen sending a fax you can specify a StatusCallback URL. If you do so, your specified URL will receive POST requests with the following parameters:| Parameter | || ----------------------------------------------------------------: | --------------------------------------------------------------------------------------------------- || RemoteStationId optional | The transmitting subscriber identification (TSID) reported by the fax machine that sent in the fax. || FaxStatus optional | The status of the fax. || OriginalMediaUrl optional | The original URL passed when a fax is sent. || NumPages optional | The number of pages received from a successful fax. || MediaSid optional | The SID that uniquely identifies the fax media. || MediaUrl optional | The media URL to request to retrieve incoming media. || ErrorCode optional | The error code provides more information on a failed fax. || ErrorMessage optional | The message explaining the reason for fax failure. |