Summary
Outlook for iOS will require iOS 26 or later starting mid-September 2026, supporting only the two latest iOS, iPadOS, and watchOS versions. Users on older versions may lose updates and syncing. Organizations should identify affected devices, notify users, and encourage OS upgrades. No admin changes needed.
Microsoft 365 Message Center ID: MC1462923
Last Modified: August 28, 2026
Category: Plan for change
Tags: New feature, User impact, Admin impact
Status: Launched
Products & Platforms: Exchange Online
Microsoft Message
To help ensure optimal performance, reliability, and security, Outlook for iOS is updating its minimum supported operating system requirements. Following the release of iOS 27, Outlook for iOS will support only the two most recent versions of iOS, iPadOS, and watchOS. This change aligns with Microsoft’s commitment to supporting the latest Apple platforms.
Rollout schedule
Worldwide, GCC, GCC High, DoD: We will begin rolling out in mid-September 2026 and expect to complete by late September 2026.
Impact on your organization
Who is affected
Users accessing Outlook on iPhone, iPad, or Apple Watch devices running operating system versions that will no longer be supported.
Platforms and services
- Outlook for iOS
- iOS
- iPadOS
- watchOS
What will happen
After iOS 27 becomes generally available:
- Outlook for iOS will no longer receive updates on devices running iOS 18 or earlier.
- Users on iOS 18 can continue using the last supported version of Outlook. However, over time, the app may stop syncing email and calendar data.
- Support for iPadOS 18 and watchOS 11 will also end.
- Supported versions will include iOS 26 and iOS 27, iPadOS 26 and iPadOS 27, and watchOS 26 and watchOS 27.
- This change does not affect users running iOS 26 or later.
Action required / Recommendations
- Review your mobile device inventory and identify devices running operating system versions that will no longer be supported.
- Notify affected users of the upcoming operating system requirement changes.
- Encourage users to upgrade eligible devices to iOS 26 or later before the rollout begins. This will help users continue receiving Outlook updates and avoid potential service interruptions.
- Review options for devices that cannot be upgraded to a supported operating system version.
- Update your internal support documentation and user communications as appropriate.
No Microsoft 365 admin configuration changes are required for this update.