Is your Outlook Calendar not syncing correctly with Todoist? Are events missing or changes not reflecting as expected? If you’re running into issues with the Outlook Calendar integration, follow these troubleshooting steps to get everything working smoothly again.
Recurring date limitations
Tasks with recurring dates will sync as recurring events in Outlook Calendar. There are, however, a few exceptions:
- When a recurrence isn’t supported by Outlook Calendar, Todoist creates a regular event for the current occurrence, then creates a new one when the next occurrence comes up.
- Rescheduling the current task occurrence to a different day or time won’t sync the change to the recurring event in Outlook Calendar.
Updating the recurrence in Outlook Calendar will generally sync back to Todoist; however, there are two scenarios that don’t sync:
- Updating a single instance of an event (“this event only”)
- Complex custom recurrences (“every day except Friday”)
Unsupported recurrences
- Every 1st month, 10th
- Every 10th day, 15th day
- Every 1st mon, 2nd tues
- Every
Xmonths - Multiple days and months (for example: every March 1, 10 April)
- Hourly recurrence (for example: every 2 hours)
- Any recurrence based on completion date (every!)
- Multiple days of a month (for example: every 2nd, 14th, 28th of each month)
- Multiple weekdays in the same month (for example: every 2nd and 4th Friday)
Calendar permissions
Todoist is a trusted Microsoft partner, and the Outlook Calendar integration follows Microsoft’s recommended OAuth security flow. The integration requests only the necessary permissions:
- Calendars.ReadWrite – Allows Todoist to read and write events in your calendars. This enables you to view calendar events in Todoist and sync scheduled tasks as Outlook events.
- email – Grants access to your email address to confirm which account is connected to Todoist.
These permissions apply to both personal Outlook accounts (live.com) and Microsoft 365 accounts (office365.com). For more details, see Microsoft’s permissions overview or the Todoist Security and Privacy FAQ.
If you've granted the appropriate calendar permissions, but you're still having issues with the integration, these troubleshooting steps may help resolve them:
Refresh your calendar manually
When you add a new calendar or change an existing calendar's color, Outlook doesn’t notify Todoist of these changes. To refresh your calendar list to show these updates:
- Log in to Todoist at https://todoist.com.
- Click your avatar at the top-left.
- Select Settings.
- Click the Calendars tab.
- Click the Resync button. Todoist will update your calendar list.
Check Microsoft 365 admin consent
For Microsoft 365 Education or Business accounts (office365.com), admin approval might be required to access the Outlook Calendar integration. This happens when Microsoft organizations restrict third-party app consent.
If you see a message indicating that admin approval is needed when trying to connect, request access from your Microsoft 365 admin with the following details:
- Application Name: Todoist for Outlook Calendar
- Application (Client) ID: abdc6ca6-1e22-47a1-aaf9-3265b713b1a8
Your admin can grant organization-wide consent to Todoist by following the steps in Microsoft’s Entra ID documentation.
If your organization has an admin consent workflow, submit a request when connecting Outlook to Todoist. Your admin can then review and approve your request.
After approval, reconnect your Outlook Calendar in Todoist and Resync to ensure everything works properly.
Log in to the correct Outlook account
If you have two or more Outlook accounts, and you initially logged in with one of these, Todoist may consistently and automatically log in to that account without giving you the option to choose another account. To fix this:
- Log in to Todoist at https://todoist.com.
- Click your avatar at the top-left.
- Select Settings.
- Click the Calendars tab.
- Disconnect the Outlook integration.
- Revoke calendar access to the Microsoft account:
- Log in to the correct Microsoft account.
- Reconnect the calendar integration.
Common issues
Here are some of the common issues with the Outlook Calendar integration, and steps to resolve them:
Todoist tasks aren't visible
If your Todoist tasks aren't visible after you've successfully connected your Outlook account, check if you've clicked “Show all” in the Outlook calendars list. Select the Todoist calendar from the list to make it visible in Outlook
Out of Sync
An “Out of sync” message in your Outlook Calendar settings means Todoist can’t retrieve your calendar data because of specific errors.
-
403 forbidden error: Todoist doesn’t have permissions to access your calendar’s data because third-party apps have limited access to your account. Admins may also be limiting third-party app access to only a group of mailboxes via an application access policy.
Contact your admin to ensure that the Todoist app has
Calendars.ReadWriteandemailpermissions granted. -
404 not found error: Todoist can't access the calendar's data. You may, for example, see this error: The mailbox is either inactive, soft-deleted, or is hosted on-premise. It means you could be missing a valid Microsoft Office 365 license.
Contact your admin to check that you have a valid license for your account.
Couldn't connect your account
If you see a “Couldn’t connect your account” pop-up message after trying to connect Outlook Calendar to Todoist, check the following:
- Click Accept on the Microsoft permissions screen that comes after clicking “Connect Outlook Calendar”.
- Check if you've enabled specific browser security settings. For example, Microsoft Edge has a “Strict” security setting that will block connections to any third-party app.
Duplicate events from shared calendars
When integrating both your personal and shared Outlook calendars into Todoist, you might notice duplicate events from these calendars. This is because events from shared calendars are synced alongside your personal events, leading to duplicates when both calendars contain the same event.
If you prefer to hide events from your shared calendars in Todoist:
- Click your avatar at the top-left.
- Select Settings.
- Click the Calendars tab.
- Click the visibility icon beside the Outlook Calendar to hide its events.
Events appear at the incorrect time
When calendar events in Todoist or Outlook Calendar appear at incorrect times, review your account time zone in both apps. In Todoist, make sure to choose a geographical timezone (for example: Europe/Paris), rather than a GMT+HH timezone. Check if your device is set to the same time zone.
If you change the time zone in Outlook Calendar, and calendar events appear at incorrect times in Todoist or vice versa, follow these steps:
- Click your avatar at the top-left.
- Select Settings.
- Select the Calendars tab.
- Toggle the Sync tasks to calendar option off.
- Wait for 10-20 seconds.
- Toggle the same option on again.
Get in touch
If you’ve tried these steps and are still having issues, get in touch with us, sharing details of the issue, including any error messages you see.