The monthly service plan charge for the line remains $0/mo. for the life of the line and requires you to keep all current phone lines on your account active through June 30, 2021. Any modifications to your account, such as cancelling an existing line, changing plans on your account or transferring lines to another account may make you ineligible to continue receiving the Unlimited Line On Us Plan.
So, looks like you have to keep your existing line (becomes paid lines) and then you can get 1 line free.
Typical tmobile type offer to retain you by making you sign up for more and more lines until you have far too many and are paying more than what you started with.
Most report it is not working with kickstart lines but a few say it did.
Can't add a free line if you only have a Kickstart plan. I have one Kickstart line from the April $300 GC offer and adding a free line with this new offer is not possible.
