Hey guys, I thought I would update this thread with my experience trying to get two AT&T numbers from two different regions on the same family plan.
I was successful at doing this. However, I tried for several hours doing it the way it was mentioned above (calling that 1-888 number that bugger mentioned) and got nowhere. I talked to 3 or 4 different CSRs and finally asked for a manager to set up the account and all I kept getting was that it was impossible to do without a verified Small Business and Tax ID#. I was so frustrated I finally decided to give up and go another route (**which will be explained at the bottom of this post). After calling my girlfriend (the other number I wanted to add to the account) she calmed me down and we decided to just go to an AT&T store to set up the family plan.
Later that day we went to the AT&T store and I told them EXACTLY what I wanted, no lying about fake small business or back stories. I mentioned that I KNOW FOR A FACT that I can merge two different numbers from two different regions into one family account and that it can be done by setting up an NBI (National Billing Instance) account and adding the numbers to it. The rep in the store said that yes, it is possible to merge the numbers on an NBI account without a Tax ID# but he would have to get a manager or someone who know the older system to do it. I was in luck and 30 minutes later walked out with a much cheaper phone bill and my same number!
I did not have to pay any fees or provide any tax info. However, whoever is claiming the "billing responsibility" on the account will have a credit check ran with their social security number for each number on the new account. This is also free for you. If you have a FAN (discount from your job) only one can be applied to your NBI account. So, if you both have a FAN discount, make sure whomever has the biggest discount is the account holder...(I had 10%, she had 18%!!)
At the end of the day, our bills were combined under a family play, both still had the same numbers, and the total was $20 cheaper than we were paying (making room for the $30 data plan for our new iPad).
To sum up, GO TO THE AT&T STORE. It's absolutely much easier and less aggravating. It most definitely will work.
**Alternative**
My alternative to this would be to find another number you would like (mine had TOOTS in the number...) then use a service such as Google Voice to forward your old number to your new number. This can be a little tricky so make sure you know exactly how to do it before starting the process. My suggestion would be to go to the AT&T store and get their opinion on how to port your old number to Google Voice without loosing it. Once you get everything done, anyone that calls your old number will go through Google Voice and forwarded to your new number seamlessly without anyone ever knowing you had a new number.
Hope this helps!!
