Apple Pay without phone - watch only?
Must I have my phone and watch, or can I pay with my watch only (and my phone is at home)?
Apple Watch Series 2
Hi
Once one or more cards have been added to Apple Pay on your Apple Watch, then it can be used entirely independently of your iPhone and of the physical payment card.
More information:
Set up Apple Pay on your iPhone, iPad, Apple Watch, or Mac - Apple Support
Using Apple Pay in stores, and within apps and websites - Apple Support