Cannot complete basket for smartwatch

[Tom951]

Used the website to upgrade from a Z Fold 3 to a S23 Ultra yesterday. There was no option to "add a smartwatch" while doing so, and trying to add a seperate item wouldn't work because "you already have an order open in the basket". So I finished the upgrade and went to do the smartwatch separately. I can only get to step 4 out of 5 before it greys out the continue button and says "To order a smartwatch, you'll need a Pay Monthly phone line to link it to. If you've already got one, just log in."

Is this likely to be something to do with the whole "you need to be on the new Three Your Way system but you're still on the old system" thing? 

[Ciaragh]

I would advise not getting a smart watch with three. They don't work and the customer service is shocking. I'm on week 5 of having the watch and everyone's passing the blame to each other. I was meant to have a call back after 7 days, it's now been 14. There are plenty of people who say the same. 

If you go ahead, best of luck.