Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Based on my research, Microsoft Authenticator does not provide a real-time synchronization feature that automatically keeps accounts synchronized between an iPhone and iPad. For personal Microsoft accounts, you may be able to use the backup and recovery feature to restore supported accounts to another iOS device. For work or school accounts, you may need to sign in and re-register the account on the additional device, depending on your organization's authentication configuration.
For Microsoft 365 work or school accounts, Microsoft Authenticator does not automatically synchronize all account credentials between devices. When restoring from a backup, only the account list is backed up, and you may need to sign in and complete MFA registration again on the new device.
If you use Microsoft Authenticator with a personal Microsoft account, you can use the Cloud Backup feature. On your iPhone, enable iCloud Backup and Authenticator backup. Then, on your iPad, install Microsoft Authenticator and use the recovery option to restore the backup. This can restore supported accounts without requiring you to add each one manually.
Back up your accounts in Microsoft Authenticator | Microsoft Support
So, if your Authenticator contains mainly personal accounts, backup and recovery can help avoid adding each account individually. If it contains business accounts, some manual re-registration may still be required after the restore process.
I hope this information helps and if you have any further questions, please feel free to ask via comment section!
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