The basic setup: what you need before you start

Syncing Outlook with iPhone means your calendar events appear on both devices and stay in sync when you make changes. You need an iPhone running iOS 16 or later, an Outlook account (Microsoft 365, Outlook.com, or an Exchange account through your employer), and the Outlook app installed on your phone. If you use only the built-in Calendar app on iPhone, you can still sync Outlook — it just takes a different path than using the Outlook app itself.

The sync happens in real time once you set it up, so an event you add on your phone shows on your computer within seconds, and vice versa. You do not need to manually refresh or upload anything. The connection stays active as long as you stay signed in.

Key Takeaways

  • The Outlook app on iPhone syncs automatically once you sign in with your Microsoft account, and you can choose which calendars to display.
  • If you prefer the built-in Calendar app, you can add your Outlook account through Settings > Mail > Accounts, and iOS will sync events in the background.
  • Two-factor authentication on your Microsoft account requires you to use an app password instead of your regular password when signing in on iPhone.
  • Synced events stay current across devices, but deleting an event on one device removes it from all devices — there is no undo from the phone.
  • If sync stops working, signing out and back in usually fixes it; clearing the app cache is the next step if that does not work.

Using the Outlook app to sync your calendar

read the Outlook app from the App Store if you do not have it. Open it and tap Sign In. Enter your Microsoft email address (the one tied to your Outlook calendar) and your password. If your account uses two-factor authentication, you will be asked to verify your identity — check the Microsoft Authenticator app on your phone or use the code sent to your email.

Once you are signed in, tap the calendar icon at the bottom of the screen. You will see a list of your calendars on the left side. Tap the eye icon next to any calendar name to show or hide it. By default, your main Outlook calendar is already visible. Any changes you make in the Outlook app — adding an event, moving it to a different time, or deleting it — sync to your Outlook account and appear on your computer within seconds.

The Outlook app also lets you see other people's calendars if they have shared them with you. Shared calendars appear in the same list and sync the same way as your own.

Using the built-in Calendar app instead

If you prefer to use iPhone's Calendar app rather than the Outlook app, you can add your Outlook account directly. Open Settings, scroll down and tap Mail, then tap Accounts. Tap Add Account and choose Outlook.com (even if your email address ends in @outlook.com, @hotmail.com, or is a work account through Microsoft 365).

Enter your email address and password. If you have two-factor authentication turned on, use an app password instead of your regular password — see the section below on how to create one. After you sign in, iOS will ask which information to sync. Make sure Calendars is toggled on. Tap Save.

Your Outlook calendar now appears in the Calendar app under the Calendars list on the left. Events sync in the background without you opening the Outlook app. Any event you create in the Calendar app on your iPhone automatically goes into your Outlook calendar.

Creating an app password if you use two-factor authentication

If your Microsoft account has two-factor authentication enabled, you cannot use your regular password to sign in on iPhone. Instead, you need to create a separate app password — a one-time code that works only for that device.

Go to account.microsoft.com on a computer and sign in. Click your profile picture in the top right, then click View account. On the left side, click Security. Under "Password security," click Create a new app password. Microsoft will show you a 16-character password. Copy it. On your iPhone, when prompted for a password during sign-in, paste this app password instead of your regular one. You only need to do this once per device.

If you lose the app password, you can create a new one the same way. The old one stops working automatically.

Troubleshooting when sync stops working

If events stop appearing on your iPhone or changes are not syncing, the first step is to sign out and sign back in. In the Outlook app, tap your profile picture at the top left, then tap Settings. Scroll down and tap Sign Out. Wait 10 seconds, then sign back in with your email and password. This refreshes the connection and usually fixes sync problems.

If you are using the built-in Calendar app and sync is not working, go to Settings > Mail > Accounts, tap your Outlook account, then tap Delete Account. Wait a few seconds, then add it again using the steps above. This clears any stuck data and resets the sync.

If signing out and back in does not work, try clearing the app cache. In the Outlook app, tap your profile picture, then Settings. Scroll down to Offline Settings and tap Clear Cache. Sign out, close the app completely, wait 30 seconds, then open it again and sign back in.

What happens when you edit or delete events

Once sync is working, any change you make on your iPhone appears on your computer and vice versa. If you edit an event on your phone — changing the time, adding a note, or inviting someone — those changes show up in Outlook on your computer within seconds. If someone else changes a shared calendar event on their computer, you see the update on your phone the same way.

Deleting an event on your iPhone removes it from your Outlook calendar everywhere. There is no trash or undo — the event is gone from all devices. If you delete something by mistake, you can create a new event with the same details, but you cannot recover the original.

If you have recurring events (like a weekly meeting), editing one instance on your phone will ask whether you want to change just that event or the whole series. Choose carefully, because the change applies to all future instances if you select the series.

Managing multiple calendars and shared calendars

If you have more than one Outlook calendar (for example, a personal calendar and a work calendar), both appear in the Outlook app once you sign in. You can show or hide each one by tapping the eye icon next to its name. In the built-in Calendar app, they appear under the same account in your Calendars list.

If a coworker or family member has shared their calendar with you, it shows up automatically in both the Outlook app and the built-in Calendar app. You can see their events but usually cannot edit them unless they gave you that permission. Shared calendars sync the same way as your own — changes appear within seconds.

To stop viewing a shared calendar, tap the eye icon next to it to hide it. This does not remove the calendar from your account; it just hides it from view. You can show it again anytime.

Frequently Asked Questions

Do I need to use the Outlook app, or can I just use the built-in Calendar app?

You can use either one. The built-in Calendar app syncs Outlook calendars just as well as the Outlook app does. Choose whichever you prefer — the Outlook app has more features like email and task management in one place, but the Calendar app is simpler if you only care about events.

Will my iPhone calendar sync back to Outlook on my computer?

Yes. Any event you create on your iPhone goes into your Outlook calendar automatically. Changes work both ways — computer to phone and phone to computer.

What if I have an Exchange account through my employer instead of a personal Outlook account?

The setup is the same. Choose Outlook.com when adding the account in Settings, enter your work email address, and sign in. Your employer's Exchange calendar syncs exactly like a personal Outlook calendar.

Can I sync multiple Outlook accounts on the same iPhone?

Yes. Add each account separately in Settings > Mail > Accounts, or sign in to each one in the Outlook app. All calendars appear together and sync independently.

If I delete an event on my iPhone by mistake, can I get it back?

Not from your phone. The deletion syncs when ready to Outlook on your computer. You would need to create a new event with the same details. Some employers keep calendar backups, so contact your IT department if the event was work-related and important.