Connecting to Office 365 Calendar with OAuth 2.0

In this article, you will learn how to connect to your Office 365 Calendar using an encrypted OAuth 2.0 connection.

When you connect to your Office 365 Calendar with an encrypted OAuth 2.0 connection, OnceHub does not store your password. Instead, a token generated by Microsoft is used to communicate with the Office 365 API. In order to maintain security, the Office 365 password expires automatically after 90 days. When this happens, your Office 365 Calendar is disconnected from OnceHub. This means that you will have to reconnect to Office 365 every 90 days.

If you would rather not reconnect every 90 days, you can connect your Office 365 calendar using an app-specific password.

Important To connect OnceHub to your Office 365 Calendar, you must have a calendar in Outlook on the web for business (Outlook Web App), which is provided with Exchange Online.

To connect to your Office 365 Calendar using an encrypted OAuth 2.0 connection:


1. Log in to your OnceHub account and navigate to ScheduleOnce. 

2. Go to Setup and open the left sidebar. Select Integrations -> Calendar integration.

Important If you are switching to Office 365 Calendar from a different calendar, you will need to disconnect from that calendar first. All future events scheduled with your previous calendar will be automatically synced with your connected Office 365 Calendar.

Figure 1: Connect to Office 365 Calendar from the Calendar integration lobby

3. In the Office 365 Calendar box, click Connect (Figure 2). A new tab will open, asking you to enter your Office 365 credentials. Once you’re done, click Sign in.

Figure 2: Connect to Office 365 Calendar

4. Your OnceHub and Office 365 accounts are now connected. You can receive reminders in your connected Office 365 calendar when events are created via ScheduleOnce.

5. To configure default Office 365 Calendar alerts, simply select an option from the Default Office 365 Calendar reminders drop-down list. (see Figure 3)

Figure 3: Default Office 365 Calendar reminders

Now you only need to configure which calendar(s) ScheduleOnce should create appointments in. To do this, just follow these steps:

1. Go to Setup -> Relevant Booking page -> Associated calendars.

  • A list of your Office 365 Calendars will appear, with your default calendar marked as the Main booking calendar. You can change this by checking the box for another calendar in the Main booking calendar column.

NoteThe connection to Office 365 can only retrieve calendars under your ownership. Shared calendars and resource calendars are not supported through the Office 365 API.

2. Select any other calendar you wish to retrieve busy time from or that you’d like to add ScheduleOnce bookings to and click Save.

3. Your ScheduleOnce Booking page is now completely integrated with your Office 365 Calendar. Learn more about configuring your Calendar settings

The last thing to do is to test it out to make sure ScheduleOnce bookings appear in your calendar. Simply access your Booking page link in your Booking page Overview section and schedule an appointment with yourself using a different email than the one you used to sign up. Once the booking has been made, check your Office 365 Calendar to make sure a calendar event has been created for the meeting with the relevant alert.

NoteWhile in beta, InviteOnce only supports Google calendar integration.

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