Which Apple Watch and iPhone do you use, and to which region is your Apple Account registered?
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Note: Siri AI is available in beta on watchOS 27 or later on Apple Watch Series 9 and later, Apple Watch Ultra 2 and later, and Apple Watch SE 3 when paired with an Apple Intelligence-enabled iPhone 15 Pro, iPhone 15 Pro Max, or iPhone 16 model or later with Siri and device language set to a supported language. Available in English to start. Siri AI will not initially be available in the EU on iOS and watchOS. Usage limits may apply.
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Not all features are available in all areas and on all models. For more information, see watchOS Feature Availability.
*Apple Intelligence is available with Siri and device language set to Chinese (Simplified), Chinese (Traditional), Danish, Dutch, English, French, German, Italian, Japanese, Korean, Norwegian, Portuguese, Spanish, Swedish, Turkish, or Vietnamese. Some features may not be available in all regions or languages. Some devices may not be available in all regions. Siri AI is available in beta in iOS 27, iPadOS 27, macOS 27, watchOS 27, and visionOS 27 and requires an Apple Intelligence–enabled device set to a supported language. Available in English to start. Siri AI will not be initially available in the EU on iOS, iPadOS, and watchOS. Certain Apple Intelligence features that rely on server-side models are subject to daily usage limits, including but not limited to Siri AI, Intelligent Photo Editing Tools, Image Playground, and AFM 3 Cloud models in Shortcuts. Daily limits may vary by feature, request complexity, system demand, system policies, and other factors. Expanded access to such features will be available for a fee in the future. Use of these features is subject to the Apple Intelligence Terms and Conditions. Learn more at apple.com/apple-intelligence.
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copied from: What’s new in watchOS 27 - Apple Support