Apple designed it so that a single Apple Watch would be paired with a single iPhone.
That doesn't mean you can't use your Apple Watch with multiple iPhones if you really want to, like your home and work iPhone, or yours and your significant other's iPhone. But it does mean it will take some work. In short, you'll need to pair, un-pair, and re-pair your Apple Watch every time you switch iPhones. Yeah, really. The good news is: we can walk you through it!
How to switch your Apple Watch from one iPhone to another
- Pair your first iPhone with your Apple Watch using the Apple Watch app.
- When you want to switch, un-pair your first iPhone, also using the Apple Watch app. (This will create a backup of your Apple Watch configuration and store it on your iPhone.)
- Pair your second iPhone with your Apple Watch.
- When you want to switch back, un-pair your second iPhone using the Apple Watch app.
- Re-pair your first iPhone, this time choosing Restore from backup to preserve as many of your settings and customizations as possible.
To continue switching between iPhones, repeat the process, un-parining and re-pairing each time
Note: Since Apple Watch backups are stored on the iPhone, any changes you make while using your first iPhone won't carry over to your second. If you want everything to be the same each time, you'll need to repeat any app or glance installations, and redo any configuration changes, every time you switch from one to the other.
Total pain, absolutely. That's why work arounds have the word work in them!