How to disconnect an apple watch from your phone

On iPhone: Open the Watch app > All Watches > Info (i) > Unpair Apple Watch. Then, enter password > Unpair.
On Watch: Press the crown > Settings > General > Reset > Erase All Content and Settings > Erase all.
Unpair using the iPhone if you need to remove Activation Lock protection.

This article explains how to unpair an Apple Watch from an iPhone, using either the iPhone or Apple Watch. Information applies to Apple Watches running watchOS 6 or later and to the iPhone Watch app in iOS 15 through iOS 10.

You might want to unpair your Apple Watch from your iPhone if you plan to sell or give away the watch or if you plan to get a newer watch. Here's how to unpair your Apple Watch using the iPhone.

Tap the Apple Watch app on the iPhone.
Tap All Watches (or My Watch) at the top of the screen.
Tap the Info (i) icon next to your watch.
Tap Unpair Apple Watch.
If you have an Apple Watch with cellular data capability, you need to indicate what to do with your monthly cellular plan. If you plan to pair this Apple Watch and iPhone again, tap Keep Plan. If you're going to pair a different Apple Watch and iPhone combination, tap Remove Plan. Tap to confirm.
Enter your Apple ID password when prompted to do so. This is necessary if you want to turn off features such as Activation Lock and Find My Watch.

You don't need to remove Activation Lock if you're going to pair the Apple Watch with another iPhone you own, but if you're going to sell it or give it away, you should remove it. The new owner won't be able to use the watch while it's still locked to your account.
Tap Unpair Apple Watch > Unpair [Name] Apple Watch.

The unpairing process takes a few minutes because the data on the watch is backed up to your iPhone. When your Apple Watch reboots to the language-choice screen, you've completed unpairing it from your iPhone.

You can also unpair the Apple Watch using the watch itself. Doing so returns the watch to factory settings, but it doesn't remove Activation Lock. To do that, you must unpair the watch using the iPhone as described above.

Only use this method if you plan to use the Apple Watch with another iPhone you own or a new iPhone.

To unpair the two devices on the watch without removing Activation Lock:
Press the Apple Watch crown to open the apps screen.
Tap the Settings icon.
Tap General.
Scroll down and tap Reset.
Tap Erase All Content and Settings.
Enter your password. For cellular models, choose to keep or remove your cellular plan on the watch.

If you aren't going to keep your cellular plan, contact your carrier to cancel the service.
Select Erase all. This action returns your Apple Watch to factory settings.

A copy of your Apple Watch data is backed up to the iPhone before it is erased.

If you plan to upgrade your phone following this unpairing process, make a backup of the old phone. When you unpaired your Apple Watch from the phone, as described above, the data from your Apple Watch was backed up on your phone.

Activate the new iPhone and restore the backed-up data (which includes the watch data) onto it.

Follow the standard steps to pair your Apple Watch with your new iPhone when the new phone is set up.

FAQ

Why won't my Apple Watch pair with my phone?

If your Apple Watch won't pair, check your watch's connection, make sure Bluetooth is enabled on your iPhone, then update and reboot both devices. If you still have trouble, clear the iPhone's network settings.
Why did my Apple Watch unpair?

Your Apple Watch can get unpaired if you turn off Bluetooth on your iPhone, or if you turn on Airplane mode on either device.