Help with Apple Watch (cellular) and 2 Lines

[AngusW]

So I'm looking at trying out an apple watch with cellular service. I've got two lines on my iPhone and each is from a different carrier. Which one would be the one paired with the watch or do they both end up pairing with the watch?

 

[oeagleo]

So I'm looking at trying out an apple watch with cellular service. I've got two lines on my iPhone and each is from a different carrier. Which one would be the one paired with the watch or do they both end up pairing with the watch?

The one that you choose, you have to go into the carrier's website/store and have it set up, and pay the money for the added line/watch.

 

[AngusW]

Ok thanks that's what I thought but wanted to check first. So now I know which carrier to go to and buy the watch.