You can’t use an Apple device without an Apple ID. You need it to download apps from the App Store on an iOS device. On macOS, you can download apps from outside the Mac App store but a lot of them are only available there. Once you connect an Apple ID to either of these devices, it also triggers other services one of which is Instant Hotspot on iOS.
Instant Hotspot on iOS allows other Apple devices like Macs and iPads that use the same Apple ID to activate the hotspot on your iOS device. You never have to interact with your iPhone. The hotspot will just turn on from a different device. If you don’t like this feature, and are looking for an off switch, you’re going to be disappointed. There is no off switch but that doesn’t mean you can’t disable Instant Hotspot on iOS. You can but it comes with a downside.
Disable Instant Hotspot
Instant Hotspot relies on your Apple ID to work but it works through iCloud. If you sign out of iCloud on your iOS device, you will not be able to turn the hotspot on from your Mac.
If you sign out of iCloud, you will have to forgo using services like Find my phone, clipboard sync, and Keychain syncing to your Mac. Decide if you’re willing to let it go and then proceed with signing out of iCloud.
Open the Settings app and tap your account at the top. On the Apple ID screen, scroll all the way to the bottom. Tap the Sign Out option. You will see a menu asking if you want to sign out of iCloud or the Store, or both. Tap the iCloud option.
That should do the trick but it obviously has limitations. If you want to be able to use Find my phone, you can try using a different Apple ID to sign into iCloud.
Apple’s ecosystem is great but it doesn’t give users fine grain control over its features, especially the ones that work between different devices. You can disable iCloud sync for individual apps but for some reason, not for Instant Hotspot. There’s nothing in any settings panel that can disable it and in some cases, this could actually be a security problem.
Users have been wanting a way to turn this off for a while and Apple’s community forums are a testament to this. This feature is a few years old and Apple isn’t likely to change it any time soon.