# Receive Notifications
source: https://developer.mastercard.com/commercial-event-notifications/documentation/use_cases/receive_notifications/index.md

Once you have created an active subscription, matching notifications will be sent to the URL that you specified at enrollment, using HTTP POST commands. Multiple notifications
may be combined into a single HTTP message.

At the destination URL, you must instantiate a server that will accept push notifications from the Commercial Event Notifications service with the following characteristics:

* Accept mutual TLS connections from Mastercard at the agreed URL and port number
* Accept and promptly acknowledge with a HTTP 200 status, HTTP POST requests from Mastercard that contain one or more notification messages

Diagram receive-notifications

Your server must be available to accept notifications at all times. If your server is planned to be unavailable for a lengthy period,
you should either disable your subscriptions or contact Mastercard to ensure that appropriate action is taken.
The Commercial Event Notifications service will retry delivery of notifications for a limited period if the destination is unavailable.

There is a small but finite chance that the same notification may be delivered more than once. Take steps in your application to check unique information
in the notification content to prevent processing the same notification multiple times should this situation arise.

The message request body will contain one or more notifications, contained in a [notification payload](https://developer.mastercard.com/commercial-event-notifications/documentation/parameters/notifications/notifications/index.md).

In the [Reference Application Tutorial](https://developer.mastercard.com/commercial-event-notifications/documentation/reference_application_tutorial/index.md) we provide a skeleton server implementation that receives and processes event notifications.