Scenario:You have an iPhone and have been syncing your calendar via iTunes, and everything has been working fine. You’ve recently added your work Exchange account to your iPhone and now have multiple calendars – calendars on the iPhone, and your Exchange account.

Problem: You keep entering new appointments on the wrong calendar, so the appointments aren’t syncing over-the-air with your Exchange calendar.

Question: How do I delete the local calendars and just have the one Exchange calendar?

Answer:

  1. Plug your iPhone into iTunes, go to the Info tab, and uncheck Sync Calendars with Outlook.
    1. Perform a sync, then unplug your iPhone.
  2. Assuming you already have your Exchange account set up…
    1. On your iPhone go to Settings > Mail, Contacts, Calendars.
  3. Select your Exchange account.
  4. Turn off Calendars.
    1. You will be prompted with a message warning you that calendar data will be deleted from the iPhone. This is fine, you will be enabling the calendar later.
  5. Exit the Settings and go to the iPhone home screen.
  6. Now go back to Settings > Mail, Contacts, Calendars.
  7. Select your Exchange account.
  8. Turn on Calendars.
    1. You will be prompted to keep or replace the calendar data on the iPhone.
    2. **WARNING** Following the next step will delete all existing calendar data on your iPhone.
    3. Choose replace.

And that should do it. You should now only have your one Exchange calendar on your iPhone.