Unpair and erase your Apple Watch
Unpairing your Apple Watch restores it to its factory settings.
Before you start
If you have the iPhone that your Apple Watch is paired with, you should follow the steps to unpair your Apple Watch. This removes Activation Lock from your Apple Watch as well as erasing all its content and settings. If you don't have the paired iPhone, you can erase your Apple Watch, but Activation Lock will remain.
If you're using your Apple Watch with a transit card in the Wallet app, remove your transit card from your Apple Watch before you unpair.
Apple Watch doesn't have a physical SIM slot or reset button — the holes in your Apple Watch case are there to allow sound to and from the microphone and speakers, and to allow water-depth measurement on Apple Watch Ultra. To avoid damage, don't insert any object into the holes in your Apple Watch case.
How to unpair and erase your Apple Watch if you have your iPhone
Keep your Apple Watch and iPhone close together as you unpair them.
Open the Apple Watch app on your iPhone.
Go to the My Watch tab and tap All Watches.
Tap the info button
next to the watch that you want to unpair. 
Tap Unpair Apple Watch.
Tap Unpair [your Apple Watch name].
For GPS + Cellular models, choose whether to keep or remove your cellular plan.
If you want to pair your Apple Watch and iPhone again, keep your plan.
If you don't want to pair your Apple Watch and iPhone again, remove your plan. If you aren't going to pair with a different watch or iPhone, you might need to contact your carrier to cancel your cellular subscription.
Type your Apple Account password to disable Activation Lock, then tap Unpair.
Before erasing all content and settings on your Apple Watch, your iPhone creates a new backup of your Apple Watch. You can use the backup to restore a new Apple Watch. After your Apple Watch unpairs, you'll see the Start Pairing message.
Now you can set up your Apple Watch again or turn it off if you're selling it or giving it away.
How to erase your Apple Watch if you don't have your iPhone
On your Apple Watch, tap Settings > General > Reset > Erase All Content and Settings.
Type your password if prompted.
For GPS + Cellular models, choose to keep or remove your cellular plan.
If you want to pair your Apple Watch and iPhone again, keep your plan.
If you don't want to pair your Apple Watch and iPhone again, remove your plan. If you aren't going to pair with a different watch or iPhone, you might need to contact your carrier to cancel your cellular subscription.
Tap Erase All to confirm. This resets your Apple Watch to the factory settings.
Now you can set up your Apple Watch again. You'll need the Apple Account and password associated with the watch turn off Activation Lock.
Erasing all content and settings erases all media, data, and settings from your Apple Watch, but it does not remove Activation Lock. To remove Activation Lock, unpair the watch first. Before your watch is erased, a backup of its contents is created on your iPhone.
Learn more
Find out what to do if you forgot your Apple Watch passcode.
