about the watches
do all apple watches have to have their own phone line
do all apple watches have to have their own phone line
Well, my carrier charges an additional $10/month for the Watch service. As I understand it, that's pretty standard in the U.S.
I understand that but what about the separate fee for the watch
There are GPS only models and GPS + Cellular models.
The GPS + Cellular models have the capability to make cellular phone calls away from your iPhone. You do not need to activate the cellular hardware, and if you choose that route, then this model will work just like the GPS only models.
If your iPhone carrier supports the GPS + Cellular Apple Watch, then you can activate the cellular hardware by adding the Apple Watch to your existing iPhone cellular plan. There is almost always an additional per month fee added to your iPhone bill on the order of $10 U.S. The Apple Watch gets the same phone number as your iPhone (although it may have an account number that looks like a phone number for billing purposes).
If you get the GPS only Apple Watch, or do not activate the cellular hardware, then this Apple Watch can do "Everything" the activated cellular Apple Watch can do, as long as your iPhone is nearby, or the Apple Watch is on a WiFi network.
The follow 2 webpage may help understand the capabilities of the Apple Watch GPS only vs Cellular
What the Apple Watch GPS-only can do without an iPhone
https://support.apple.com/en-us/HT205547
https://www.imore.com/heres-what-apple-watch-can-do-without-iphone
Apple Watch Carriers, in case you want to know if your iPhone carrier supports the Cellular model.
The Apple Watch 3 with cellular and Apple Watch 4 with cellular can share a SIM with a phone on a supported network. No Apple watch can have it's own phone number.
about the watches