why is my outlook calendar not syncing with iphone

If you use multiple accounts on your Mac like iCloud, Gmail, and Yahoo, make sure that iCloud is your default Contacts account: If you store and edit your contacts in iCloud instead of another place, like On My Mac, Exchange, or Google, then iCloud automatically updates your contacts. In the General tab, make sure that one of your iCloud calendars is the default.In macOS Monterey or earlier, choose Calendar > Preferences. If you use multiple accounts on your Mac like iCloud, Gmail, and Yahoo, make sure that iCloud is your default Calendar account: If you store and edit your events in iCloud instead of another place, like On My Mac, Exchange, or Google, then iCloud automatically updates your calendars. Set iCloud as the default account for your contacts:

If you don't see the contact you're looking for, it's stored in another account.

Tap Done to see your list of contacts.

Deselect the All option for any third-party account, like Gmail or Yahoo.

Open the Contacts app and tap Groups in the upper-left corner.

If you have a copy of your contacts from a third-party service in vCard format version 3.0 or later, you can import the contacts into iCloud.

Tap Lists in the upper-left corner, then tap 'All ' to check each individual account set up for Contacts.

If you don't see the contact you're looking for, it might be stored in a different account.

Select 'All iCloud' to see your list of contacts in iCloud.Open the Contacts app and tap Lists in the upper-left corner.

To see which account your contacts are in:

Why is my outlook calendar not syncing with iphone