AT&T, 2 lines and the new iPhone

[circleswerun]

So here's my situation. I have a line that's due for an upgrade on June 6th. I currently have a 3GS on another plan. I'd like to upgrade the older line, use the new iPhone on my new line and (eventually) cancel the first line. (I heard you have to keep the line for 30 days or you have to give the phone back)

Here are a couple questions I have:

When upgrading line #1, will I get hit with an activation fee for the new iPhone?

Can I remove the data plan immediately so I'm not getting charged an extra $30 a month for the first month?

I don't have a sim card for line #1 anymore. Will that be a problem?

Is there any other problems I'm not thinking about that I might run into?

Thanks for the help.

 

[geko29]

If you upgrade the old line, you will have a 2yr contract on that line. So even if you move the phone to the new(er) line, you'll still have to keep paying for the old line for another 24 months.

 

[RonHC]

lol this is the same question from the Apple Forum in the AT&T website
Yes, you will have to pay the $30 for both

If you are trying to use the upgrade from the other line to replace your iPhone on your line, then just call them ahead of time and tell what you are doing