Calendar sync on iPhone and iPad: fix common issues

When events show up on your iPhone but not your iPad, the cause is almost always a setting that differs between the two. Check these in order:

1. iCloud Calendar is on for both devices. One switch turned off is enough to break it.
2. Both devices use the same Apple Account. If the email under your name differs, they sync to different calendars.
3. Google and Outlook accounts are added on both devices. Adding one to your iPhone doesn't add it to your iPad.
4. Fetch New Data isn't set to Manual. Manual means the device only checks when you open the app.
5. Busy time reaches your other accounts. Apple's settings show every calendar, but they don't block time across them.

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You add a dinner reservation on your iPhone, and later it's missing on your iPad. That's how double bookings and missed appointments happen.

This is rarely a hardware problem. It's usually one setting that doesn't match, and you can fix it in a few minutes.

Why your iPhone and iPad aren't syncing

Your iPhone and iPad don't sync with each other directly. Each one syncs with the account that holds the calendar, whether that's iCloud, Google or Outlook. If one device isn't connected to that account, it never gets the events.

The usual causes:

• iCloud Calendar is turned off on one device.
• The devices are signed in to different Apple Accounts.
• You added your Google or Outlook calendar to one device but not the other.

Start with the first one.

Check your iCloud settings

If you use Apple's own calendar, iCloud carries your events between devices. The calendar setting has to be on for both.

On your iPhone:

1. Open Settings.
2. Tap your name at the top.
3. Tap iCloud.
4. In the list of apps using iCloud, find Calendars and make sure it's on.

Then check the same setting on your iPad.

If it was off on one device, turn it on and give it a couple of minutes. If it was already on for both, switching it off and on again often clears a stuck sync.

Make sure you're using the same Apple ID

This sounds obvious, but it's a common reason calendars don't sync. Apple now calls the Apple ID an Apple Account.

To check:

1. Open Settings on your iPhone.
2. Tap your name and look at the email address shown.
3. Do the same on your iPad.

If the addresses don't match, the devices sync to two different iCloud calendars. Either sign in with the same Apple Account on both, or share the calendars you need from one account to the other through iCloud calendar sharing.

How to sync Google and Outlook calendars

This is where a lot of people get stuck. Adding your Google or Outlook account to your iPhone doesn't add it to your iPad. You have to add it on each device.

On both your iPhone and your iPad:

1. Open Settings and go to the Calendar settings. On newer iOS versions, Calendar is listed under Apps.
2. Open the accounts section and tap Add Account.
3. Choose Google or Outlook and sign in.
4. Make sure Calendars is turned on for that account.

Your iPad then reads events straight from your Google or Outlook account, the same way your iPhone does.

Blocking busy time across accounts

Apple's settings put every account's events on your screen, but they don't copy busy time from one account to another. A colleague booking time in your work Outlook calendar still sees your slot as free, even though your personal Google Calendar has a dentist appointment in it.

Caltsu fixes that for Google and Microsoft accounts. It creates "Busy" blocks in your other calendars when an event is added to one of them. Because those accounts are already in Apple's Calendar app, the blocks show on your iPhone and iPad too. Caltsu doesn't sync iCloud calendars yet.

Still not working? Try these troubleshooting tips

If every setting above checks out and events still don't appear, try these.

1. Check your "Fetch" settings

• In the Calendar accounts settings, open Fetch New Data.
• Turn on Push if your account supports it.
• For accounts that don't support Push, such as Google, choose a fetch interval like every 15 minutes instead of Manual.

2. Check your default calendar

• In the Calendar settings, open Default Calendar and make sure it's the one you expect.
• In the Calendar app, tap Calendars and check that the calendars you want to see are selected.

3. Check your date and time settings

• Go to Settings > General > Date & Time.
• Turn on Set Automatically on both your iPhone and your iPad.

Keep your Apple devices in sync

For most people the fix is one of two things. Sign in with the same Apple Account on both devices with iCloud Calendar turned on, and add your Google or Outlook accounts to each device separately.