For those of you following this thread, here is the response I got, from AT&T, to my question. Hope this helps.
My question:
Hi, I currently have an iPhone 3G and am not eligible for an upgrade
till May 2010. One of my friends is buying an iPhone 3G S on 06/19/09.
My question is can I swap my phone with hers and both of us keep our
respective numbers? We are not on the same plan. Thanks in advance.
Answer from AT&T:
Dear xxxxx xxxxxx,
Thank you for taking the time to e-mail AT&T regarding swapping a phone
with a friend that is purchasing the iPhone 3G S. My name is Stacy
Wells, and I am happy to help you with your inquiry.
If your friend is purchasing an iPhone 3G S and would like to trade with
you for the iPhone 3G, you may do so. Simply take the SIM card from your
phone and place it in the new iPhone 3G S and vise versa. You will need
to contact Customer Care at 1-800-331-0500 with the 2 phones available
as well as your friend if you are not on the same account. We will need
to change the equipment information for each phone in question. The IMEI
numbers, which is a serial number that tells the kind of phone that is
being used, will need to be moved from one phone to the other. You can
find this number on either phone by pressing *#06# on phone and the
number will display on the screen. You will then call Customer Care and
have them place the right IMEI number with the correct phone.
Do keep in mind that the 2 year contract will apply to the line that is
originally completing the upgrade as well as the $18 upgrade fee. Also
both lines will still be required to have the $30 iPhone data feature
and accept all Terms of Service related to the activation and usage of
each phone.
We greatly appreciate the opportunity to serve you since 2006. Please let us know if we can assist in any other way, and
thank you for choosing AT&T. Again my name is Stacy Wells, and if this
answers all of your questions, then there is no need to reply back. Be
sure to take advantage of our online services at
www.wireless.att.com
for all of your account needs. To send additional requests via email,
please follow these steps:
1. Log in to your "My Wireless" page at
www.wireless.att.com
2. Click on contact us, which is located by the search link on the top
right hand corner of page
3. Scroll down to bottom and select the link to email us.
4. Follow prompts to send us an email.
If you would like to comment on my service, please complete the online
survey via the link located below.
Sincerely,
Stacy Wells
AT&T
Online Customer Care Professional
Please allow me to remind you of our * Services.