# Notifications

Webhooks allow you to get updates in real-time about the status of your faxes. Webhooks are triggered by events such as the completion of a fax, and transmit information about the state of that fax to you via HTTP(S) or email.
HTTP webhooks are multipart/form-data POST requests, and should be processed like form submissions.
**Note:** When webhooks with Basic authentication credentials are shown in GET requests, the credentials are masked with `***`` symbols. It is not possible to retrieve previously-set credentials through the API.

 - [Setting up webhooks](https://developers.sinch.com/docs/fax/api-reference/fax/notifications/setting-up-webhooks.md): ## Setting up webhooks Depending on the type of webhook, you can configure the callback URLs in a few ways: **Incoming fax notification**: - On your [Fax service](https://dashboard.sinch.com/fax/servi
 - [Retries](https://developers.sinch.com/docs/fax/api-reference/fax/notifications/retries.md): ### Retries If a webhook fails, we will automatically retry sending the fax up to 16 times. There will be a delay before each retry, which increases as follows: | Retry number | Delay | Cumulative wai
 - [IP Addresses](https://developers.sinch.com/docs/fax/api-reference/fax/notifications/ip-addresses.md): ### IP Addresses Notifications are sent from the following IP addresses so you can add them to allowlists if necessary. | IP address | Description | | --- | --- | | 34.232.249.173 | use1 (East) | | 4
 - [POST incomingFax](https://developers.sinch.com/docs/fax/api-reference/fax/notifications/incomingfaxevent.md): This webhook is triggered when a fax is received on a Sinch number associated with a service. The webhook will contain information about the fax, such as the sender, the recipient, and the content of
 - [POST faxCompleted](https://developers.sinch.com/docs/fax/api-reference/fax/notifications/faxcompletedcallback.md): Triggered when the fax has been completed. The callback will contain information about the fax, such as the sender, the recipient, and the content of the fax. You must set the callback URL where you w